#include<iostream> 
using namespace std;
int main() 
{	
	int c,y;
	cin>>c>>y; 
	int r=c%y; 
	while (r!=0)
	{
		c=y; 
		y=r;
		r=c%y; } 
	cout<<y<<endl;
	return 0; 
}

#include using namespace std; int main() { int m,n;
cin>>m>>n; int r=m%n; while (r!=0) { m=n; n=r; r=m%n; } cout<<n<<endl; return 0; }

#include using namespace std; int main() { int m,n; scanf("%d %d",&m,&n); int r=m%n; while(r!=0) { m=n; n=r; r=m%n; } printf("%d",n); return 0; }