diff --git a/Cargo.lock b/Cargo.lock
index e9a8c36..b455533 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7,9 +7,21 @@ name = "adventofcode2024"
 version = "0.1.0"
 dependencies = [
  "itertools",
+ "memoize",
  "regex",
 ]
 
+[[package]]
+name = "ahash"
+version = "0.7.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "891477e0c6a8957309ee5c45a6368af3ae14bb510732d2684ffa19af310920f9"
+dependencies = [
+ "getrandom",
+ "once_cell",
+ "version_check",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.3"
@@ -19,12 +31,38 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "either"
 version = "1.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"
 
+[[package]]
+name = "getrandom"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4567c8db10ae91089c99af84c68c38da3ec2f087c3f82960bcdbf3656b6f4d7"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a9ee70c43aaf417c914396645a0fa852624801b24ebb7ae78fe8272889ac888"
+dependencies = [
+ "ahash",
+]
+
 [[package]]
 name = "itertools"
 version = "0.13.0"
@@ -34,12 +72,80 @@ dependencies = [
  "either",
 ]
 
+[[package]]
+name = "lazy_static"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+
+[[package]]
+name = "libc"
+version = "0.2.168"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aaeb2981e0606ca11d79718f8bb01164f1d6ed75080182d3abf017e6d244b6d"
+
+[[package]]
+name = "lru"
+version = "0.7.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e999beba7b6e8345721bd280141ed958096a2e4abdf74f67ff4ce49b4b54e47a"
+dependencies = [
+ "hashbrown",
+]
+
 [[package]]
 name = "memchr"
 version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
+[[package]]
+name = "memoize"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5df4051db13d0816cf23196d3baa216385ae099339f5d0645a8d9ff2305e82b8"
+dependencies = [
+ "lazy_static",
+ "lru",
+ "memoize-inner",
+]
+
+[[package]]
+name = "memoize-inner"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "27bdece7e91f0d1e33df7b46ec187a93ea0d4e642113a1039ac8bfdd4a3273ac"
+dependencies = [
+ "lazy_static",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.20.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1261fe7e33c73b354eab43b1273a57c8f967d0391e80353e51f764ac02cf6775"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37d3544b3f2748c54e147655edb5025752e2303145b5aefb3c3ea2c78b973bb0"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "regex"
 version = "1.11.1"
@@ -68,3 +174,32 @@ name = "regex-syntax"
 version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
+
+[[package]]
+name = "syn"
+version = "1.0.109"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "adb9e6ca4f869e1180728b7950e35922a7fc6397f7b641499e8f3ef06e50dc83"
+
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
diff --git a/Cargo.toml b/Cargo.toml
index 5c2abc8..ecd8d4c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,4 +5,5 @@ edition = "2021"
 
 [dependencies]
 itertools = "0.13.0"
+memoize = "0.4.2"
 regex = "1.11.1"
diff --git a/input/11-0.in b/input/11-0.in
new file mode 100644
index 0000000..9b26c84
--- /dev/null
+++ b/input/11-0.in
@@ -0,0 +1 @@
+125 17
diff --git a/input/11-1.in b/input/11-1.in
new file mode 100644
index 0000000..a0509bc
--- /dev/null
+++ b/input/11-1.in
@@ -0,0 +1,3 @@
+64599 31 674832 2659361 1 0 8867 321
+
+
diff --git a/src/bin/11.rs b/src/bin/11.rs
new file mode 100644
index 0000000..8a7f9b7
--- /dev/null
+++ b/src/bin/11.rs
@@ -0,0 +1,42 @@
+use memoize::memoize;
+
+#[memoize]
+fn num_stones(x: u64, depth: u64) -> u64 {
+    if depth == 0 {
+        return 1;
+    }
+
+    if x == 0 {
+        num_stones(1, depth - 1)
+    } else if (x.ilog10() + 1) % 2 == 0 {
+        let length = x.ilog10() + 1;
+        let split = 10u64.pow(length / 2);
+        num_stones(x / split, depth - 1) + num_stones(x % split, depth - 1)
+    } else {
+        num_stones(x * 2024, depth - 1)
+    }
+}
+
+fn main() {
+    let text = std::fs::read_to_string("input/11-1.in").unwrap();
+
+    let depth = 25;
+
+    let t = text
+        .trim()
+        .split(' ')
+        .map(|w| num_stones(w.parse::<u64>().unwrap(), depth))
+        .sum::<u64>();
+
+    println!("{t}");
+
+    let depth = 75;
+
+    let t = text
+        .trim()
+        .split(' ')
+        .map(|w| num_stones(w.parse::<u64>().unwrap(), depth))
+        .sum::<u64>();
+
+    println!("{t}");
+}