1*5971e316Smrg for (int c0 = 0; c0 <= n / 10; c0 += 1) 2*5971e316Smrg for (int c1 = 10 * c0; c1 <= min(n, 10 * c0 + 9); c1 += 1) 3*5971e316Smrg S1(c0, c1); 4