23102 - 求最大公约数(提高版)

#include<bits/stdc++.h>
using namespace std;
int main(){
	long long a,b,y;
	cin>>a>>b;
	while(a%b!=0){
		y=a%b;
		a=b;
		b=y;
	}
	cout<<b;
	return 0;
}