1 for (int c0 = 1; c0 <= n; c0 += 1) {
2   S1(c0, c0);
3   for (int c1 = c0; c1 <= n; c1 += 1)
4     S2(c0, c1);
5   S3(c0, n);
6 }
7 for (int c0 = n + 1; c0 <= m; c0 += 1)
8   S3(c0, n);
9