#include<bits/stdc++.h>
using namespace std;
int a[15]={6,2,5,5,4,5,6,3,7,6},l,r,h1,sum1,sum2,ma=-1,ans=1;
int main(){
//	freopen(".in","r",stdin);
//	freopen(".out","w",stdout);
	cin>>l>>r;
	for(int i=l;i<=r;i++){
		h1=i,sum1=0;
		while(h1){
			sum1+=a[h1%10];
			h1/=10;
		}
		if(sum1==sum2)ans++;
		else{
			ma=max(ma,ans);
			ans=1;
		}
		sum2=sum1;
	}
	cout<<ma;
	return 0;
}