【板子】世界上最美的GCD

#include<bits/stdc++.h>
using namespace std;

#define ll long long

ll Gcd(ll x,ll y){while(y^=x^=y^=x%=y);return x;}

int main()
{
    ll a,b;
    cin>>a>>b;
    cout<<Gcd(a,b);
    return 0;
}