#include <cstdio>
#include <iostream>
#include <cstring>
#include <string>
using namespace std;

int a[10];
int dp[10][2][2];

int dfs(int u, bool is6, bool have, bool limit)
{
    if(u < 1)    return !have;
    if(!limit && dp[u][is6][have] != -1)    return dp[u][is6][have];
    
    int maxn = limit ? a[u] : 9;
    int ret = 0;
    
    for(int i=0; i<=maxn; i++) {
        ret += dfs(u-1, i==6, have||i==4||(is6&&i==2), limit&&i==maxn);
    }
    if(!limit)    dp[u][is6][have] = ret;
    return ret;
}

int f(int n)
{
    int len=0;
    while(n) {
        a[++len] = n%10;
        n /= 10;
    }
    return dfs(len, 0, 0, 1);
}

int main ()
{
    int n, m;
    memset(dp, -1, sizeof(dp));
    while(scanf("%d%d", &n, &m) != EOF && (m|n)) {
        printf("%d\n", f(m) - f(n-1));
    }
    return 0;
}