for (int c0 = 2; c0 <= 8; c0 += 2)
for (int c1 = 1; c1 <= 9; c1 += 1) {
if (c0 % 4 == 0)
s0(c1, c0);
s1(c1, c0);
}
for (int c0 = 2; c0 <= 8; c0 += 2)
for (int c1 = 1; c1 <= 9; c1 += 1) {
if (c0 % 4 == 0)
s0(c1, c0);
s1(c1, c0);
}