void main()
{
	int x,y,i,countx,county,c,p,q;
	int a[11]={0},b[11]={0};
	scanf("%d %d",&x,&y);
	countx=1;
	county=1;
	c=0;
	p=x;
	q=y;
	while (p!=1)
	{
		countx++;
		p=p/2;
	}
		while (q!=1)
	{
		county++;
		q=q/2;
	}
		for(i=countx;i>=1;i--)
		{
			a[i]=x;
			x=x/2;
		}
		for(i=county;i>=1;i--)
		{
			b[i]=y;
			y=y/2;
		}
		for (i=1;i<=10;i++)
		{
			if(a[i]==b[i]&&a[i]!=0&&b[i]!=0) c=a[i];
			else break;
		}
	printf("%d",c);
}
/*int days(int month,int day)
{
	int z=0;
	int k;
	if (month==1) z=day;
	else
	{
		for(k=1;k<month;k++)
		{
			if(k==1||k==3||k==5||k==7||k==8||k==10||k==12) z+=31;
			else if (k==2) z+=28;
			else z+=30;
		}
		z+=day;
	}
	return z;
}*/