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;
}