diff --git a/cpp/2210/221020.cpp b/cpp/2210/221020.cpp
new file mode 100644
index 0000000..254b44e
--- /dev/null
+++ b/cpp/2210/221020.cpp
@@ -0,0 +1,39 @@
+#include <string>
+#include <iostream>
+
+/**
+ * 12. Integer to Roman
+ *
+ * No desc since clear
+ */
+
+class Solution {
+public:
+	static std::string intToRoman(int num) {
+		static const char* s = "IVXLCDM";
+		std::string ret;
+		for (int i = 0; i < 6; i += 2, num /= 10) {
+			int n = num % 10;
+			if (n == 4 || n == 9) {
+				ret.push_back(s[i + 1 + (n > 5)]);
+				ret.push_back(s[i]);
+			} else {
+				ret.append(n % 5, s[i]);
+				if (n >= 5) ret.push_back(s[i + 1]);
+			}
+		}
+		ret.append(num, 'M');
+		std::reverse(ret.begin(), ret.end());
+		return ret;
+	}
+};
+
+int main() {
+	for (int i = 1; i <= 50; ++i) {
+		std::cout << Solution::intToRoman(i) << "\n";
+	}
+	std::cout << Solution::intToRoman(3) << "\n";
+	std::cout << Solution::intToRoman(58) << "\n";
+	std::cout << Solution::intToRoman(1994) << "\n";
+	return 0;
+}
diff --git a/cpp/2210/CMakeLists.txt b/cpp/2210/CMakeLists.txt
index c5d055b..b8cde8e 100644
--- a/cpp/2210/CMakeLists.txt
+++ b/cpp/2210/CMakeLists.txt
@@ -3,4 +3,4 @@ PROJECT(2210)
 
 SET(CMAKE_CXX_STANDARD 23)
 
-ADD_EXECUTABLE(2210 221020-CN.cpp)
+ADD_EXECUTABLE(2210 221020.cpp)