//
//  main.cpp
//  hdu2089
//
//  Created by Candy on 13/11/2016.
//  Copyright © 2016 Candy. All rights reserved.
//

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
using namespace std;
typedef long long ll;
const int N=10;
int l,r;
int d[N][4];
void dp(){
    d[0][0]=1;
    for(int i=1;i<=6;i++){
        d[i][0]=9*d[i-1][0]-d[i-1][1];
        d[i][1]=d[i-1][0];
        d[i][2]=10*d[i-1][2]+d[i-1][1]+d[i-1][0];
    }
}
int a[N];
int sol(int n){
    int len=0,tn=n,ans=0;
    while(n) a[++len]=n%10,n/=10;
    a[len+1]=0;
    int flag=0;
    for(int i=len;i>=1;i--){
        ans+=d[i-1][2]*a[i];
        
        if(flag) ans+=a[i]*d[i-1][0];   //begin skyline
        else{
            if(a[i]>4) ans+=d[i-1][0];//maybe 4
            if(a[i+1]==6&&a[i]>2) ans+=d[i][1];//maybe 62
            if(a[i]>6) ans+=d[i-1][1];//maybe 62
        }
        if(a[i]==4||(a[i+1]==6&&a[i]==2)) flag=1;//has unlucky
    }
    return tn-ans;
}
int main(int argc, const char * argv[]) {
    dp();
    while(scanf("%d%d",&l,&r)&&l+r)
        printf("%d\n",sol(r+1)-sol(l));
    return 0;
}