diff --git a/aoc_12a/.gitignore b/aoc_12a/.gitignore
new file mode 100644
index 0000000..62bd1a4
--- /dev/null
+++ b/aoc_12a/.gitignore
@@ -0,0 +1,12 @@
+# ---> Rust
+# Generated by Cargo
+# will have compiled files and executables
+/target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
diff --git a/aoc_12a/Cargo.toml b/aoc_12a/Cargo.toml
new file mode 100644
index 0000000..9142f44
--- /dev/null
+++ b/aoc_12a/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "aoc_12a"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/aoc_12a/input b/aoc_12a/input
new file mode 100644
index 0000000..9dfe1f5
--- /dev/null
+++ b/aoc_12a/input
@@ -0,0 +1,41 @@
+abccccccccccccccccccccccccccaaaaaaaaacccccccccccaaacccccccccccccccccccccccccaaaaaaaaccccccccaaaaaaccaaccccccccccccccccccccccccaaaaacaacaaaacccccccccccccccccccccccccccccccccccccaaaaa
+abccaaacccccccccccccccccccccaaaaaaaaacccccccccaaaaaacccccccccccccccccccccaaaaaaaaaaaccccccccaaaaaaccaaaaaacccaacaaccccccccccccaaaaaaaacaaaaaaccccccccccccccccccccccccccccccccccaaaaaa
+abccaaaaccccccccccccccccccccaaaaaaaaccccccccccaaaaaaccccaaaaaccccccccccccaaaaaaaaaaacccccccccaaaaaccaaaaaccccaaaacccccccccccccccaaaaacccaaaaaccccccccccccccccccccaaccccccccccccaaaaaa
+abccaaaacccccccaaaccccccccccaaaaaaacccccccccccaaaaaaccccaaaaaccccccccccccacaaaaaaaaaacccccccaaaaacaaaaaaacccaaaaaccccccccccccccaaaaacccaaaaaccccccccccccccccccccaaaaccccccccccccccaaa
+abccaaaccccccaaaaaacccccccccaccaaaccccccccccccaaaaacccccaaaaaaccccaaaacccccaaaaaaaaaaaccccccaaaaacaaaaaaacccaaaaaacccccccccccccaacaaaccaccaacccccccccccccccaaaccaaaaccccccccccccccaaa
+abcccccccccccaaaaaacccccccccccccaaacccccccccccaaaaacccccaaaaaaccccaaaaccccccaaaaacaaaaccccccccccccccaaaaaaccacaaaaccccaaaaacccccccaaccccccccccccccccccccccaaaackkkaccccccccccccccccaa
+abcccccccccccaaaaaacccccccccccccccaaacccccccccccccccccccaaaaaaccccaaaacccccaaaaaccccaaccccccccccccccaaccaaccccaaccccccaaaaaccccccccccccccccccccccccccccccccaakkkkkkkccccccccccccccccc
+abaccccccccccaaaaaccccccccccccccccaaaaccccccccccccccccccccaaaccccccaaccccccccaaaccccccccccccccccccccaacccccccccccccccaaaaaacccccccccccccccccccccaaacccccccccjkkkkkkkkccccccccaacccccc
+abaccccccccccaaaaacccccaacccccccccaaaaccccccccccccaacccccccccccccccccccccccccaaacccccccccccccccccccccaaccccccaccaccccaaaaaaaaaccaccccccccccccccaaaaccccccccjjkkoopkkkkaccaacaaacccccc
+abaccccccccccccccccaaaaaacccccccccaaacccccccccccccaaaaaacccccccccccccccccccccccccccccccccccccccccccccaaaaaaccaaaaccccaaaaaaaaacaaccccccccccccccaaaacccccccjjjkoooppkkkaccaaaaaaaacccc
+abcccccccccccccccccaaaaaaaaccccccccccccccccaccccccaaaaaaccccccccccccccccccccccccaaccaacccccccccccccccaaaaaacaaaaacccccaaacccaaaaacccccccccccccccaaacccccjjjjjoooppppkklccaaaaaaaacccc
+abcccccccccccccccccaaaaaaaacccccccccccccccaaacccaaaaaaaccccaacccacccccccccccccccaaaaaaccccccccaaaccaaaaaaaccaaaaaaccccccccaaaaaacccccccccccccccccccccjjjjjjjoooouuppplllccaccaaaacccc
+abccccccccccccccccccaaaaaaaccccaacccccaaacaaacccaaaaaaaccccaaacaacccccccccccccccaaaaaacccccccccaaaaaaaaaaaacaaaaaaccccccccaaaaaaaaccccccccccccccccciijjjjjjooouuuupppllllcccccccccccc
+abccccccccccccccccccaaaaaccccccaacccccaaaaaaaaaaccaaaaaaccccaaaaaccccccccccccccaaaaaaacccccccaaaaaaaaaaaaaacccaaccccccccccaacaaaaacccccccccccccccciiiijoooooouuuuuuppplllllcccccccccc
+abcccccccccccccccccaaaaaacccaacaaaaacccaaaaaaaaaccaaccaaccaaaaaacccccccccccccccaaaaaaaaccccccaaaaacccaaaaaacccaccccccccccccccaacccccccccccccccccciiiinnoooooouuxuuuupppplllllcccccccc
+abcccccccccccccccccccccaacccaaaaaaaaccccaaaaaaccccaaccccccaaaaaaaaccaaaccccccccaaaaaaaacccccccaaaaaccaacaaaaaaaacccaaccccccccacccccccccaaaccccccciiinnnnntttuuuxxuuuppppqqllllccccccc
+abccccccccccccaacccccccccccccaaaaaccccccaaaaaacccccaaaccccaaaaaaaaccaaaacccccccccaaaccccccccccaaccaccccccaaaaaacccaaaaaaccccccccccccccaaaaccccaaiiinnnntttttuuxxxxuuvpqqqqqllmmcccccc
+abccccccccccaaaaaaccccccccccccaaaaaccccaaaaaaacccccaaacccccccaacccccaaaaccccaaccccaacccccccccccccccccccccaaaaaaccccaaaaaccccccccccccccaaaaccccaaiiinnnttttxxxxxxxyuvvvvvqqqqmmmcccccc
+abccaaacccccaaaaaacccccccccccaaacaaccccaaacaaacccccaaaaaaacccaccccccaaaccccaaaacccccccccccccccccccccccccaaaaaaaacaaaaaaacccccccccaaacccaaaccccaaaiinnntttxxxxxxxxyyyyvvvvqqqmmmcccccc
+abcaaaacccccaaaaaccccccccccccaaaccaccccccccccacccaaaaaaaaaaccccccccccccccccaaaaccccccccccccccccccccccccaaaaaaaaaaaaaaaaaaccccccccaaaaaacccccaaaaaiiinnnttxxxxxxxyyyyyyvvvqqqmmmcccccc
+SbcaaaaccccccaaaaacccccaaaccccccaaacccccccccaaccaaaaaaaaaaaacccccccccccccccaaaaccccccccccccccccccccccccaaaaaaaaaaaaaaaaaacccccccaaaaaaacccccaaaaaiiinnntttxxxxEzzyyyyvvvqqqmmmdddcccc
+abccaaaccccccaaaaacccccaaaaccccaaaaaaccccccaaaaccaaaaaaacaaacccccaaccccccccccccccccccccccccccccccccccccacaaaaacccccaaacacccccccaaaaaaaccccccaaaaaahhhnnntttxxxyyyyyyvvvvqqmmmmdddcccc
+abcccccccccccccccccccccaaaaccccaaaaaaccccccaaaaccccaaaaaaaaaaaaaaaacacccccccccccccccccccccccccccccccccccccaaaacccccaaccccccccccaaaaaaaccccccccaaaahhhnnnnttxxxyyyyyvvvqqqqmmmdddccccc
+abcccccccccccccccaacaacaaacccccaaaaaaccccccaaaacccaaaaaaaaaaaaaaaaaaacccccccccccccccccaacaaccccccccccccccccaaccccccccccccccccccccaaaaaacccccccaaccchhhmmmttxwyyyyyyvvrqqqmmmddddccccc
+abcccccccccccccccaaaacccccccccccaaaaacccccccccccaaaaaaaaaaaaaaccaaaaccccaacccccaacccccaaaaaccccccccccccccccccccccccccccccccaaaaccaaaaaacccccccaaccahhhmmssswwywwwyyyvvrqmmmmdddcccccc
+abccccccccccccccaaaaacccccccccccaacaacccccccccccaaaaaacaaaaaacccaaaaaaacaaccccaaaccccccaaaaacccccccacccccccccccccccccccccccaaaaccaacccccccccccaaaaahhhmmsswwwwwwwwywwvrrnnmdddccccccc
+abccccccccccccccaaaaaaccaaccccccccccccccccccccccaaaaaaaaaaaaacccacaacaaaaaccccaaacaaacaaaaaacaaacaaacccccccacccaaccccaaccccaaaacccccccccaaaccccaaaahhhmmssswwwwswwwwwwrrnnndddccccccc
+abaaccccccccccccacaaaacaaaaaaaccccccccccaacccccccaaaaaaaacaaaccccccccaaaaaaaaaaaaaaaacaaaacccaaaaaaacccccccaacaaaaaaaaacccccaaccccccccccaaacccaaaaahhhmmsssswsssrrwwwrrrnneddaccccccc
+abaaccccccccaaccccaaccccaaaaacccccccccccaacccccccaaaacccccccacccccccaaaaaaaaaaaaaaaaacccaaccccaaaaaacccccccaaaaacaaaaaaacccccccccccccaaaaaaaaaaaaaahhhmmssssssssrrrrrrrrnneedaaaacccc
+abacccccccccaaaaccccccaaaaaaaccccccccaaaaaaaacccccccccccccccccccccccaaaaaaaacaaaaaacccaaacccccaaaaaaaacccccaaaaaacaaaaaaaccccccccccccaaaaaaaaaaaaaahhhmmmsssssllrrrrrrrnnneeeaaaacccc
+abaaacccccaaaaaaccccccaaaaaaaacccaaccaaaaaaaaccccaaaaaccccccccccccccaaaaaacccaaaaaaccccaaaccaaaaaaaaaaccccaaaaaaaaaaaaaaaccccccccccccccaaaaaccccaachhgmmmmmlllllllrrrrrnnneeeaaaacccc
+abaaacccccaaaaaccccaccaaaaaaaacaaaaaaccaaaaccccccaaaaacccccccccccccccccaaacccaaaaaaaccaaaaaaaaaaaaaaaaccccaaaaaaaaaaaaacccccccccccccccaaaaaaccccaaccgggmmmllllllllllnnnnneeeaaaaccccc
+abcccccccccaaaaacccaaacaaaacaacaaaaaacaaaaaccccccaaaaaaccccccccccccccccccccccaaacaaacccaaaaaaaacaaaccccccccccaaccaaaaaacccccccccccccccaaaaaacaacccccgggggmlllfffflllnnnnneeeaaaaccccc
+abcccccccccaaccacccaaaaaaacccccaaaaaacaacaaacccccaaaaaaccccccccccccccccccccccaccaaccaaaaaaaaacccaaaccccccccccaaccccccaacccccaaaaccccccaccaaaaaaccccccggggggggfffffflnnneeeeeacaaacccc
+abaaaccccccccccccccaaaaaacccccccaaaaacacccaaaacccaaaaaacccccccccccccccccccaaacccaaccaaaaaaaaacccaaccccccccccccccccccccccccccaaaaccccaaaccaaaaaacccccccgggggggfffffffffeeeeeaacccccccc
+abaaaaacccccccccccaaaaaaaaccccccaaaacccccccaaacccccaacccccccaaacccccccccccaaaacaaacccaaaaaaaacccccccccccccccccccccccccccccccaaaaccccaaacccaaaaaaacccccccccgccaaaafffffeeeeccccccccccc
+abaaaaaccccccaaccaaaaaaaaaacccccaaacaaaaaacaaaccccccccccccaaaaaccccccccccaaaaacaaacccccaaaaaaacccccccccccccccccccccccccccccccaacccccaaaaaaaaaaaaaccccccccccccaaaacaafffecccccccccccaa
+abaaaacccaaacaaccaaaaaaaaaacccccaaaaaaaaaaaaaaaaacccccccccaaaaaaccccccccccaaaaaaaaaaacaaacccacccaacccccccccaaaaccccaaacccccccccccaaaaaaaaaaaaaaacccccccccccccaaaccccaaccccccccccccaaa
+abaaaaacccaaaaacccccaaacaaacccccaaaaaaccaaaaaaaaacccccccccaaaaaaccaaccacccaaaaaaaaaaaaaaaccccccaaacccccccccaaaaccccaaaaccccccccccaaaaaaaaaaaaaaccccccccccccccaaaccccccccccccccccccaaa
+abaaaaacccaaaaaaacccaaaccccccccaaaaaaaaccaaaaaaaccccccccccaaaaacccaaaaaccccaaaaaaaaaaaaacccccaaaaaaaaccccccaaaaccccaaaacccccccccccaaaaaaacccaaaccccccccccccccaaacccccccccccccccaaaaaa
+abcccccccaaaaaaaaccccaacccccccaaaaaaaaaaaaaaaaacccccccccccaaaaaccaaaaaacccccaaaaaaaaaaaaaccccaaaaaaaacccccccaacccccaaacccccccccccccaaaaaaacccccccccccccccccccccccccccccccccccccaaaaaa
diff --git a/aoc_12a/input2 b/aoc_12a/input2
new file mode 100644
index 0000000..86e9cac
--- /dev/null
+++ b/aoc_12a/input2
@@ -0,0 +1,5 @@
+Sabqponm
+abcryxxl
+accszExk
+acctuvwj
+abdefghi
diff --git a/aoc_12a/src/main.rs b/aoc_12a/src/main.rs
new file mode 100644
index 0000000..b166695
--- /dev/null
+++ b/aoc_12a/src/main.rs
@@ -0,0 +1,116 @@
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::path::Path;
+use std::collections::HashSet;
+
+#[derive(Debug)]
+struct Cell {
+    altitude: u8,
+    score: Option<u32>,
+}
+
+impl Cell {
+    pub fn new(altitude: u8) -> Self {
+        Self {
+            altitude,
+            score: None,
+        }
+    }
+}
+
+fn print_map(map: &Vec<Vec<Cell>>) {
+    for y in map.iter() {
+        for x in y.iter() {
+            let c;
+            match x.score {
+                Some(n) => {
+                    let m = (n % 62) as u8;
+                    if m < 26 {
+                        c = m + b'a';
+                    }
+                    else if m < 52 {
+                        c = m + b'A' - 26;
+                    }
+                    else {
+                        c = m + b'0' - 52;
+                    }
+                },
+                None => c = b'#'
+            };
+            print!("{}", c as char);
+        }
+        println!("");
+    }
+}
+
+fn main() {
+    let file_path = String::from("input");
+    let mut map = Vec::<Vec<Cell>>::new();
+    let mut start_coor: (usize, usize) = (0, 0);
+    let mut end_coor: (usize, usize) = (0, 0);
+    println!("In file {}", file_path);
+
+    if let Ok(lines) = read_lines(file_path) {
+        // Consumes the iterator, returns an (Optional) String
+        for (y, line) in lines.enumerate() {
+            if let Ok(ip) = line {
+                map.push(ip.bytes().enumerate().map(|(x, byte)| match byte {
+                    b'a'..=b'z' => Cell::new(byte - b'a'),
+                    b'S' => {
+                        start_coor = (x, y);
+                        Cell::new(0)
+                    },
+                    b'E' => {
+                        end_coor = (x, y);
+                        Cell::new(25)
+                    }
+                    _ => panic!("Parse error"),
+                }).collect());
+            }
+        }
+    }
+
+    let height = map.len();
+    let width = map[0].len();
+    let mut cursors = vec![start_coor];
+    let mut score = 0;
+    while !cursors.is_empty() {
+        let mut new_cursors = HashSet::<(usize, usize)>::new();
+        for cursor in cursors {
+            let (x, y) = cursor;
+            let altitude = map[y][x].altitude;
+            match map[y][x].score {
+                Some(_) => (),
+                None => {
+                    map[y][x].score = Some(score);
+                    if x + 1 < width && altitude + 1 >= map[y][x + 1].altitude {
+                        new_cursors.insert((x + 1, y));
+                    }
+                    if x > 0 && altitude + 1 >= map[y][x - 1].altitude {
+                        new_cursors.insert((x - 1, y));
+                    }
+                    if y + 1 < height && altitude + 1 >= map[y + 1][x].altitude {
+                        new_cursors.insert((x, y + 1));
+                    }
+                    if y > 0 && altitude + 1 >= map[y - 1][x].altitude {
+                        new_cursors.insert((x, y - 1));
+                    }
+                },
+            };
+        }
+        score += 1;
+        cursors = Vec::<(usize, usize)>::new();
+        for cursor in new_cursors {
+            cursors.push(cursor);
+        }
+    }
+
+    print_map(&map);
+    println!("{}", map[end_coor.1][end_coor.0].score.unwrap());
+}
+
+fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
+where P: AsRef<Path>, {
+    let file = File::open(filename)?;
+    Ok(io::BufReader::new(file).lines())
+}
diff --git a/aoc_12b/.gitignore b/aoc_12b/.gitignore
new file mode 100644
index 0000000..62bd1a4
--- /dev/null
+++ b/aoc_12b/.gitignore
@@ -0,0 +1,12 @@
+# ---> Rust
+# Generated by Cargo
+# will have compiled files and executables
+/target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
diff --git a/aoc_12b/Cargo.toml b/aoc_12b/Cargo.toml
new file mode 100644
index 0000000..d1c0d68
--- /dev/null
+++ b/aoc_12b/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "aoc_12b"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/aoc_12b/src/main.rs b/aoc_12b/src/main.rs
new file mode 100644
index 0000000..1bd6c88
--- /dev/null
+++ b/aoc_12b/src/main.rs
@@ -0,0 +1,119 @@
+use std::fs::File;
+use std::io::{self, BufRead};
+use std::path::Path;
+use std::collections::HashSet;
+
+#[derive(Debug)]
+struct Cell {
+    altitude: u8,
+    score: Option<u32>,
+}
+
+impl Cell {
+    pub fn new(altitude: u8) -> Self {
+        Self {
+            altitude,
+            score: None,
+        }
+    }
+}
+
+fn print_map(map: &Vec<Vec<Cell>>) {
+    for y in map.iter() {
+        for x in y.iter() {
+            let c;
+            match x.score {
+                Some(n) => {
+                    let m = (n % 62) as u8;
+                    if m < 26 {
+                        c = m + b'a';
+                    }
+                    else if m < 52 {
+                        c = m + b'A' - 26;
+                    }
+                    else {
+                        c = m + b'0' - 52;
+                    }
+                },
+                None => c = b'#'
+            };
+            print!("{}", c as char);
+        }
+        println!("");
+    }
+}
+
+fn main() {
+    let file_path = String::from("../aoc_12a/input");
+    let mut map = Vec::<Vec<Cell>>::new();
+    let mut start_coor: (usize, usize) = (0, 0);
+    let mut end_coor: (usize, usize) = (0, 0);
+    println!("In file {}", file_path);
+
+    if let Ok(lines) = read_lines(file_path) {
+        // Consumes the iterator, returns an (Optional) String
+        for (y, line) in lines.enumerate() {
+            if let Ok(ip) = line {
+                map.push(ip.bytes().enumerate().map(|(x, byte)| match byte {
+                    b'a'..=b'z' => Cell::new(byte - b'a'),
+                    b'S' => {
+                        start_coor = (x, y);
+                        Cell::new(0)
+                    },
+                    b'E' => {
+                        end_coor = (x, y);
+                        Cell::new(25)
+                    }
+                    _ => panic!("Parse error"),
+                }).collect());
+            }
+        }
+    }
+
+    let height = map.len();
+    let width = map[0].len();
+    let mut cursors = Vec::new();
+    for y in 0..height {
+        cursors.push((0, y));
+    }
+    let mut score = 0;
+    while !cursors.is_empty() {
+        let mut new_cursors = HashSet::<(usize, usize)>::new();
+        for cursor in cursors {
+            let (x, y) = cursor;
+            let altitude = map[y][x].altitude;
+            match map[y][x].score {
+                Some(_) => (),
+                None => {
+                    map[y][x].score = Some(score);
+                    if x + 1 < width && altitude + 1 >= map[y][x + 1].altitude {
+                        new_cursors.insert((x + 1, y));
+                    }
+                    if x > 0 && altitude + 1 >= map[y][x - 1].altitude {
+                        new_cursors.insert((x - 1, y));
+                    }
+                    if y + 1 < height && altitude + 1 >= map[y + 1][x].altitude {
+                        new_cursors.insert((x, y + 1));
+                    }
+                    if y > 0 && altitude + 1 >= map[y - 1][x].altitude {
+                        new_cursors.insert((x, y - 1));
+                    }
+                },
+            };
+        }
+        score += 1;
+        cursors = Vec::<(usize, usize)>::new();
+        for cursor in new_cursors {
+            cursors.push(cursor);
+        }
+    }
+
+    print_map(&map);
+    println!("{}", map[end_coor.1][end_coor.0].score.unwrap());
+}
+
+fn read_lines<P>(filename: P) -> io::Result<io::Lines<io::BufReader<File>>>
+where P: AsRef<Path>, {
+    let file = File::open(filename)?;
+    Ok(io::BufReader::new(file).lines())
+}