diff --git a/test.c b/test.c
new file mode 100644
index 0000000..5a7edc4
--- /dev/null
+++ b/test.c
@@ -0,0 +1,31 @@
+// C
+
+#include <stdio.h>
+
+inline int gcd(int a, int b)
+{
+    if (b > 0) return gcd(b, a % b);
+    else return a;
+}
+
+int main()
+{
+    printf("test\n");
+    
+    const int N = 1000;
+    int A[N];
+    for (int i = 0; i < N; i++)
+    {
+        A[i] = i;
+    }
+
+    int ans = 0;
+    for (int i = 0; i < N; i++)
+    {
+        for (int j = 0; j < N; j++)
+        {
+            ans += gcd(A[i], A[j]);
+        }
+    }
+    printf("%d\n", ans);
+}