diff --git a/AtCoder/ABC309/A/A.cpp b/AtCoder/ABC309/A/A.cpp
new file mode 100644
index 00000000..bea11e14
--- /dev/null
+++ b/AtCoder/ABC309/A/A.cpp
@@ -0,0 +1,18 @@
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int a, b;
+
+    cin >> a >> b;
+
+    cout << (b - a == 1 && a != 3 && a != 6 && a != 9 && b != 1 && b != 4 && b != 7 ? "Yes" : "No") << endl;
+
+    return 0;
+}