1 for (int c0 = 1; c0 <= N; c0 += 1) 2 for (int c1 = 0; c1 <= min(min(M, c0), N - c0); c1 += 1) 3 for (int c2 = 0; c2 <= min(min(M, c0), N - c0); c2 += 1) 4 S1(c0, c1, c2); 5