
int main()
{
	int a,b,i,j,p,q,m[100],n[100];
	cin>>a>>b;
	m[0]=a,n[0]=b;
	if(a==1||b==1)cout<<'1'<<endl;//?????1?????????1
	else
	{
		for(i=1;;i++)
		{
			m[i]=a/2;
			a=a/2;//?????????????????
			if(a==1)break;//??????1???
		}
		for(j=1;;j++)
		{
			n[j]=b/2;
			b=b/2;
			if(b==1)break;
		}
		for(p=0;p<=i;p++)
		{
			for(q=0;q<=j;q++)
			{
				if(m[p]==n[q]){cout<<m[p]<<endl;return 0;};//?????????????
			}
		}
	}
	
}