diff --git a/Yang/3.c b/Yang/3.c
new file mode 100644
index 0000000..8ca0f13
--- /dev/null
+++ b/Yang/3.c
@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#define SIZE 1024
+
+void matmul(float** A, float** B, float** C, int n) {
+    int i, j, k;
+    for (i = 0; i < n; ++i) {
+        for (j = 0; j < n; ++j) {
+            C[i][j] = 0;
+            for (k = 0; k < n; ++k) {
+                C[i][j] += A[i][k] * B[k][j];
+            }
+        }
+    }
+}
+
+int main() {
+    float** A = (float**)malloc(SIZE * sizeof(float*));
+    float** B = (float**)malloc(SIZE * sizeof(float*));
+    float** C = (float**)malloc(SIZE * sizeof(float*));
+    int i, j;
+    for (i = 0; i < SIZE; ++i) {
+        A[i] = (float*)malloc(SIZE * sizeof(float));
+        B[i] = (float*)malloc(SIZE * sizeof(float));
+        C[i] = (float*)malloc(SIZE * sizeof(float));
+    }
+
+    srand(time(0));
+    for (i = 0; i < SIZE; ++i) {
+        for (j = 0; j < SIZE; ++j) {
+            A[i][j] = rand() % 100; 
+            B[i][j] = rand() % 100; 
+        }
+    }
+    clock_t start = clock();
+    matmul(A, B, C, SIZE);
+    clock_t end = clock();
+    double time = (double)(end - start) / CLOCKS_PER_SEC;
+    printf("%f\n", time);
+
+    for (i = 0; i < SIZE; ++i) {
+        free(A[i]);
+        free(B[i]);
+        free(C[i]);
+    }
+    free(A);
+    free(B);
+    free(C);
+    return 0;
+}
\ No newline at end of file