辗转相除法

#include <iostream>
using namespace std;
int gcd(int a, int b)
{
    if (a % b==0) return b;
    else return gcd(b, a % b);
}
int x, y;
int main(){
     
    cin >> x >> y;
    cout << gcd(x, y);
     
    return 0;
}