#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<queue>
#include<stack>
#include<algorithm>
#define int long long
using namespace std;
const int N=1e6+5;
const int INF=0x3f3f3f3f;
int n,m,a[N],dp[20][3];
int dfs(int len,int f,int flag){
	if(len==-1)return 1;
	if(!flag&&dp[len][f==6]!=0)return dp[len][f==6];
	int nid=flag?a[len]:9;
	int ans=0;
	for(int i=0;i<=nid;i++){
		if((i==4)||(i==2&&f==6))continue;
		ans+=dfs(len-1,i,flag&&i==a[len]);
	}
	if(!flag){
		dp[len][f==6]=ans;
	}
	return ans;
}
int find(int num){
	int len=0;
	while(num!=0){
		a[len]=num%10;
		len++;
		num/=10;
	}
	return dfs(len-1,-1,true);
}
signed main(){
	while(scanf("%lld%lld",&n,&m)){
		if(n==0&&m==0)return 0;
		cout << find(m)-find(n-1) << endl;
	}
	return 0;
}