int gcd0(int big, int small) {
    if (big < small) {
        swap(big, small);
    }
    if (big % small == 0) {
        return small;
    }
    return gcd0(small, big % small);
}

int gcd1(int big, int small) {
    if (big < small) {
        swap(big, small);
    }
    for (int i = small; i >= 1; --i) {
        if (big % i == 0 && small % i == 0)
            return i;
    }
    return 1;
}