diff --git a/cpp/2304/230421-CN.cpp b/cpp/2304/230421-CN.cpp
new file mode 100644
index 0000000..45dd1fb
--- /dev/null
+++ b/cpp/2304/230421-CN.cpp
@@ -0,0 +1,12 @@
+/**
+ * 2413. Smallest Even Multiple
+ *
+ * Given a positive integer n, return the smallest positive integer that is a multiple of both 2 and n.
+ */
+
+class Solution {
+public:
+	static constexpr int smallestEvenMultiple(int n) {
+		return n << (n & 1);
+	}
+};
\ No newline at end of file
diff --git a/cpp/2304/CMakeLists.txt b/cpp/2304/CMakeLists.txt
index 87d3eb6..b3b1cbb 100644
--- a/cpp/2304/CMakeLists.txt
+++ b/cpp/2304/CMakeLists.txt
@@ -4,4 +4,4 @@ PROJECT(2304)
 SET(CMAKE_CXX_STANDARD 23)
 SET(CMAKE_EXPORT_COMPILE_COMMANDS true)
 
-ADD_EXECUTABLE(2304 230419.cpp)
+ADD_EXECUTABLE(2304 230421-CN.cpp)