#include<bits/stdc++.h>
using namespace std;
long long a,b,t;
int main(){
    cin>>a>>b;
    while(a % b != 0){
        t = a % b;
        a = b;
        b = t;
    } 
    cout<<b<<endl;
      
       
       
       
       
       
       
       
       
       
       
       
       
       
       
       
       
       
       
       
       
    return 0;
}
/**************************************************************
	Problem: 1335
	User: chenmingyu
	Language: C++
	Result: Accepted
	Time:22 ms
	Memory:2072 kb
****************************************************************/