#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int a,b,i; cin>>a>>b; i=a%b; while(i!=0){ a=b; b=i; i=a%b; } cout<<b<<endl; return 0; }