diff --git a/src/cal/day01.rs b/src/cal/day01.rs
new file mode 100644
index 0000000..2af1e5b
--- /dev/null
+++ b/src/cal/day01.rs
@@ -0,0 +1,18 @@
+use axum::{extract::Path, http::StatusCode, response::IntoResponse, routing::get, Router};
+
+pub(crate) fn router() -> Router {
+    Router::new().route("/1/*ids", get(cube_bits))
+}
+
+async fn cube_bits(Path(ids): Path<String>) -> Result<impl IntoResponse, StatusCode> {
+    let res = ids
+        .split('/')
+        .map(|id| id.parse::<i32>())
+        .collect::<Result<Vec<_>, _>>()
+        .map_err(|_| StatusCode::BAD_REQUEST)?
+        .into_iter()
+        .fold(0i32, |acc, id| acc ^ id)
+        .pow(3)
+        .to_string();
+    Ok(res)
+}
diff --git a/src/cal/mod.rs b/src/cal/mod.rs
index a9dda0c..3384629 100644
--- a/src/cal/mod.rs
+++ b/src/cal/mod.rs
@@ -1,6 +1,8 @@
 mod day00;
+mod day01;
 
 pub(crate) fn router() -> axum::Router {
     axum::Router::new()
         .nest("/", day00::router())
+        .nest("/", day01::router())
 }