int main()
{
	int c(int x,int y);
	int x,y;//???x?y
	cin>>x>>y;
	cout<<c(x,y)<<endl;
return 0;
}

int c(int x,int y)//?????
{
	int z;
	if(x==y)//???????
		z=x;
	if(x>y)
		z=c(x/2,y);//???????
	if(y>x)
		z=c(x,y/2);
	return z;
}