#include<bits/stdc++.h> using namespace std;int main(){int n,m;cin>>n>>m;while(n!=0){ n = n%m;m = abs(n - m); }cout<<m;}

#include <stdio.h> int main(){ int a,b; scanf("%d%d",&a,&b); while(a!=0){a=a%b;if(a-b<0)b=b-a;else{b=a-b;}} printf("%d",b); }