diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 16b85d0..97d2a7b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -88,3 +88,8 @@ day-17:
   stage: build
   script:
     - cd day17; cargo run --release ./input
+
+day-18:
+  stage: build
+  script:
+    - cd day18; cargo run --release ./input
diff --git a/day18/Cargo.toml b/day18/Cargo.toml
new file mode 100644
index 0000000..fa53f27
--- /dev/null
+++ b/day18/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "day18"
+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/day18/input b/day18/input
new file mode 100644
index 0000000..983da28
--- /dev/null
+++ b/day18/input
@@ -0,0 +1,100 @@
+[[0,6],[[[4,0],[6,6]],[[2,2],9]]]
+[[9,[[1,6],[6,0]]],[[1,[0,8]],[[0,8],[9,8]]]]
+[[[0,[2,1]],3],[[[2,4],[1,2]],[7,5]]]
+[[[[8,3],[8,5]],[[7,8],[5,5]]],[9,2]]
+[[8,[1,9]],[[[9,9],[9,2]],1]]
+[[[[3,7],[2,1]],[0,9]],4]
+[[[[3,8],[6,0]],[0,7]],[[[6,3],[2,0]],9]]
+[[[9,[7,0]],[8,[9,6]]],[[5,6],4]]
+[[[[3,6],[3,6]],[0,2]],[[[8,3],9],[[3,4],8]]]
+[[7,[8,4]],1]
+[6,[[3,[5,6]],[0,6]]]
+[[[7,[4,7]],[[4,5],[4,3]]],[[5,5],[0,[4,2]]]]
+[[[0,[2,9]],[[2,4],[4,8]]],[[8,[9,5]],[[9,6],0]]]
+[[[[2,0],[9,7]],[[3,2],0]],[7,7]]
+[[5,[2,1]],[[3,[5,1]],[[8,5],[1,8]]]]
+[[[[9,7],6],[[7,8],7]],[[[6,8],9],[[9,5],7]]]
+[[4,2],[[[0,1],[7,2]],[[0,2],[5,5]]]]
+[[1,8],[[5,[7,9]],[[3,1],[7,1]]]]
+[[[4,[4,6]],6],5]
+[[[5,[3,6]],6],[[[8,0],[8,6]],[[3,3],[0,1]]]]
+[[4,[[2,6],[0,9]]],[[0,6],[4,2]]]
+[[[[9,4],[6,5]],7],[[[1,5],[0,9]],[4,[4,2]]]]
+[[7,[[6,5],8]],[[[5,6],0],[6,[3,5]]]]
+[[[5,[6,4]],[8,[0,4]]],[[3,[9,3]],4]]
+[[[[4,0],6],[6,[6,5]]],[[9,[6,3]],[[9,6],7]]]
+[[[[2,2],4],[8,[7,2]]],[2,1]]
+[5,[9,[[5,9],4]]]
+[[[1,[7,7]],[[2,2],8]],[[[9,7],5],[4,3]]]
+[[[[6,8],1],1],[1,[[2,0],6]]]
+[[[[0,5],8],[[8,9],[9,3]]],[[[5,5],[4,2]],2]]
+[[[9,[2,5]],[6,[1,7]]],[5,[3,[2,2]]]]
+[[[7,6],8],[[[1,9],3],[5,2]]]
+[8,[[2,[0,7]],8]]
+[[[[8,1],[0,0]],5],1]
+[[1,[[4,8],0]],[[9,[7,8]],5]]
+[[[[1,3],1],[[9,8],[6,6]]],5]
+[[[3,2],[[0,5],[0,1]]],[[9,[9,3]],[4,9]]]
+[[[0,[2,4]],[[3,3],[6,5]]],[[1,[2,1]],[[3,4],9]]]
+[[2,[3,[7,6]]],[5,5]]
+[[[[8,2],0],[[9,6],[9,0]]],[[[6,2],[5,0]],9]]
+[7,[9,7]]
+[3,[[[5,5],1],[8,5]]]
+[[[5,5],[5,6]],[9,5]]
+[[[9,7],[1,2]],[8,[5,[7,0]]]]
+[[[1,[5,2]],[7,[8,9]]],[2,[[4,5],[2,3]]]]
+[[[4,[2,2]],[5,[4,7]]],[[[0,3],2],[5,[2,6]]]]
+[[0,[[6,5],5]],[[7,[7,2]],3]]
+[[[4,[9,4]],[1,9]],[7,[[7,1],[6,1]]]]
+[1,[0,2]]
+[[[[5,1],[2,1]],[[7,8],6]],[[3,[4,9]],2]]
+[[9,[[4,0],[8,8]]],[[[6,6],[2,8]],[1,[1,5]]]]
+[[[1,2],[7,0]],[7,[[3,0],5]]]
+[[[6,[0,8]],3],[[3,7],1]]
+[[[[6,1],[1,0]],9],[[4,8],[3,[0,8]]]]
+[[6,[3,[5,8]]],9]
+[[[[5,0],[7,7]],[[3,1],[4,8]]],5]
+[[[3,7],[9,0]],[[[0,2],7],0]]
+[8,9]
+[[8,[[0,8],4]],[1,[[4,6],2]]]
+[[[5,5],3],[[6,6],[0,[6,3]]]]
+[[[7,[3,7]],[[6,1],[9,4]]],[[[8,9],1],[[8,7],6]]]
+[[6,[[0,9],[2,3]]],[[1,[5,3]],[8,4]]]
+[[[3,5],8],[[[2,4],[7,5]],5]]
+[[0,[[7,0],[9,4]]],[[[0,0],[6,7]],[6,5]]]
+[[[[1,9],[6,4]],0],[6,[3,[4,8]]]]
+[[[[1,6],[0,4]],8],[[8,8],6]]
+[[[[7,4],[9,6]],7],[[1,6],[1,0]]]
+[1,[[[6,8],5],5]]
+[8,4]
+[9,[[9,[3,9]],0]]
+[5,[[[4,9],7],[[1,0],0]]]
+[[[6,1],[0,[2,3]]],[[[7,8],[5,9]],9]]
+[3,[[3,[3,4]],[6,[7,8]]]]
+[[[7,[7,1]],[4,[2,0]]],[6,[7,3]]]
+[[6,9],[[3,[4,7]],3]]
+[1,[[9,[5,1]],[7,[7,5]]]]
+[[3,2],[[9,[6,8]],[[1,0],2]]]
+[[[[3,2],8],[7,6]],9]
+[[3,[[9,5],6]],[5,9]]
+[[[3,[6,3]],[[7,0],[5,7]]],[[3,3],[[4,9],[4,8]]]]
+[[[0,[4,3]],2],[3,[0,[1,3]]]]
+[[[7,[3,4]],[7,[3,1]]],[[0,[4,7]],6]]
+[[[1,[7,4]],[[8,7],3]],4]
+[[[5,5],[[0,3],2]],[1,[[9,4],6]]]
+[[[[6,0],[8,8]],[6,[6,0]]],[5,6]]
+[[[1,[5,4]],[[5,9],[1,7]]],[[5,[4,7]],[4,[4,4]]]]
+[[0,[[2,6],0]],[[6,[4,3]],5]]
+[[[1,[5,3]],[9,[1,2]]],[[[4,8],[5,6]],0]]
+[[0,7],[1,[7,7]]]
+[4,[[7,[7,2]],[[9,1],7]]]
+[2,[[1,6],[6,9]]]
+[[[4,[4,5]],9],[[[1,7],6],[3,[7,3]]]]
+[[6,[[1,1],[7,8]]],[[[5,2],[8,1]],5]]
+[[[5,5],[[4,1],[1,2]]],[[3,8],[3,4]]]
+[[[[1,9],[0,3]],[4,[0,9]]],4]
+[[[4,9],0],[[9,0],[8,[7,5]]]]
+[[6,[5,3]],[[[6,6],4],[[6,8],4]]]
+[[[[1,1],2],1],[1,[[6,4],2]]]
+[[[[6,3],[1,5]],[6,[7,7]]],[6,6]]
+[[[[3,0],[5,6]],1],[[[9,3],[1,7]],[[3,4],[2,7]]]]
diff --git a/day18/src/main.rs b/day18/src/main.rs
new file mode 100644
index 0000000..84e018d
--- /dev/null
+++ b/day18/src/main.rs
@@ -0,0 +1,118 @@
+use std::{fs, env};
+
+fn read_input(path: &str) -> String {
+    return fs::read_to_string(path).expect("Cannot read file.");
+}
+
+fn parse_input(s: &str) -> Vec<Vec<(u8, u32)>> {
+    let mut r = vec![];
+    for l in s.lines() {
+        let mut d = 0;
+        let mut v = vec![];
+        for c in l.chars() {
+            if c == '[' {
+                d += 1;
+            } else if c == ']' {
+                d -= 1;
+            } else if c.is_digit(10) {
+                v.push((d, c.to_digit(10).unwrap()));
+            }
+        }
+        r.push(v);
+    }
+    return r;
+}
+
+fn sum(l: &Vec<(u8, u32)>, r: &Vec<(u8, u32)>) -> Vec<(u8, u32)> {
+    let mut v = vec![];
+    v.append(&mut l.iter().map(|x| (x.0 + 1, x.1)).collect());
+    v.append(&mut r.iter().map(|x| (x.0 + 1, x.1)).collect());
+    return v;
+}
+
+fn reduce(v: &mut Vec<(u8, u32)>) {
+    while explode(v) || split(v) {}
+}
+
+fn explode(v: &mut Vec<(u8, u32)>) -> bool {
+    for i in 0..v.len() - 1 {
+        if v[i].0 > 4 && v[i + 1].0 > 4 {
+            if i > 0 {
+                v[i - 1].1 += v[i].1;
+            }
+            if i + 2 < v.len() {
+                v[i + 2].1 += v[i + 1].1;
+            }
+            v.remove(i + 1);
+            v[i].0 -= 1;
+            v[i].1 = 0;
+            return true;
+        }
+    }
+    return false;
+}
+
+fn split(v: &mut Vec<(u8, u32)>) -> bool {
+    for i in 0..v.len() {
+        if v[i].1 >= 10 {
+            let d = v[i].1 as f32 / 2f32;
+            v[i].1 = d.floor() as u32;
+            v[i].0 += 1;
+            v.insert(i + 1, (v[i].0, d.ceil() as u32));
+            return true;
+        }
+    }
+    return false;
+}
+
+fn compute(v: &Vec<Vec<(u8, u32)>>) -> Vec<(u8, u32)> {
+    if v.is_empty() { return vec![]; }
+    let mut r = v[0].clone();
+    for x in 1..v.len() {
+        r = sum(&r, &v[x]);
+        reduce(&mut r);
+    }
+    return r;
+}
+
+fn get_magnitude(mut v: Vec<(u8, u32)>) -> u32 {
+    if v.is_empty() { return 0; }
+    for d in (0..=4).rev() {
+        let mut t = vec![];
+        let mut s = false;
+        for i in 0..v.len()  {
+            if s { s = false; continue; }
+            if i + 1 < v.len() && v[i].0 == d && v[i + 1].0 == d {
+                t.push((d - 1, 3 * v[i].1 + 2 * v[i + 1].1));
+                s = true;
+            } else { t.push(v[i]); }
+        }
+        v = t;
+    }
+    return v[0].1;
+}
+
+fn get_max_magnitude(v: &Vec<Vec<(u8, u32)>>) -> u32 {
+    let mut m = vec![];
+    for a in v {
+        for b in v {
+            if a != b {
+                let c = vec![a.to_owned(), b.to_owned()];
+                m.push(get_magnitude(compute(&c)));
+            }
+        }
+    }
+    return m.iter().fold(u32::MIN, |acc, i| if *i > acc { *i } else { acc });
+}
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    for arg in args.iter().skip(1) {
+        let input = read_input(&arg);
+        let vec_in = parse_input(&input);
+        println!("[{}]", &arg);
+        println!("\t[Part 1] => Answer is '{}'.", get_magnitude(compute(&vec_in)));
+        println!("\t[Part 2] => Answer is '{}'.", get_max_magnitude(&vec_in));
+    }
+}
+