#include using namespace std; unsigned long long gcd(unsigned long long m,unsigned long long n) { int x=1; unsigned long long t; begin:if(m==n) return x*m; if(m>1; goto begin; } if(n&1) { m=m>>1; goto begin; } x=x*2; m=m>>1; n=n>>1; goto begin; } int main() { unsigned long long n,m; scanf("%lld%lld",&n,&m); printf("%lld\n",gcd(n,m)); return 0; }