diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a472820..a8a7fbf 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -63,3 +63,8 @@ day-12:
   stage: build
   script:
     - cd day12; cargo run --release ./input
+
+day-13:
+  stage: build
+  script:
+    - cd day13; cargo run --release ./input
diff --git a/day13/Cargo.toml b/day13/Cargo.toml
new file mode 100644
index 0000000..36c9510
--- /dev/null
+++ b/day13/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "day13"
+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/day13/input b/day13/input
new file mode 100644
index 0000000..b2b2c61
--- /dev/null
+++ b/day13/input
@@ -0,0 +1,934 @@
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+
+fold along x=655
+fold along y=447
+fold along x=327
+fold along y=223
+fold along x=163
+fold along y=111
+fold along x=81
+fold along y=55
+fold along x=40
+fold along y=27
+fold along y=13
+fold along y=6
diff --git a/day13/src/main.rs b/day13/src/main.rs
new file mode 100644
index 0000000..b9be444
--- /dev/null
+++ b/day13/src/main.rs
@@ -0,0 +1,71 @@
+use std::{fs, env, collections::HashSet};
+
+fn read_input(path: &str) -> String {
+    return fs::read_to_string(path).expect("Cannot read file.");
+}
+
+fn parse_input(s: &str) -> (HashSet<(i32, i32)>, Vec<(char, i32)>) {
+    let mut is_fold = false;
+    let mut t = HashSet::new();
+    let mut i = vec![];
+    for l in s.lines() {
+        if l == "" { is_fold = true; continue; }
+        if !is_fold {
+            let x = l.split_once(",").unwrap();
+            t.insert((x.0.parse().unwrap(), x.1.parse().unwrap()));
+        } else {
+            let x = l.split_once("=").unwrap();
+            i.push((x.0.chars().last().unwrap(), x.1.parse().unwrap()));
+        }
+    }
+    return (t, i);
+}
+
+fn apply_n_folds(i: &HashSet<(i32, i32)>, f: &Vec<(char, i32)>, n: usize) -> HashSet<(i32, i32)> {
+    let mut h = i.clone();
+    for x in 0..n {
+        for c in h.clone().iter() {
+            if f[x].0 == 'y' {
+                h.insert((c.0, if c.1 > f[x].1 { c.1 - (c.1 - f[x].1) * 2 } else { c.1 }));
+                if c.1 > f[x].1 {
+                    h.remove(c);
+                }
+            } else {
+                h.insert((if c.0 > f[x].1 { c.0 - (c.0 - f[x].1) * 2 } else { c.0 }, c.1));
+                if c.0 > f[x].1 {
+                    h.remove(c);
+                }
+            }
+        }
+    }
+    return h;
+}
+
+fn show_array(i: &HashSet<(i32, i32)>) {
+    let m = i.iter().map(|e| e.0).max().unwrap();
+    let n = i.iter().map(|e| e.1).max().unwrap();
+    for y in 0..=n {
+        print!("\t\t");
+        for x in 0..=m {
+            if i.contains(&(x, y)) {
+                print!("{}", '#');
+            } else {
+                print!(" ");
+            }
+        }
+        println!();
+    }
+}
+
+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 '{}'.", apply_n_folds(&vec_in.0, &vec_in.1, 1).len());
+        println!("\t[Part 2] => Answer is:");
+        show_array(&apply_n_folds(&vec_in.0, &vec_in.1, vec_in.1.len()));
+    }
+}
+