import java.io.*;
import java.util.*;

public class Main {

    private static int[][] dp;

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            String tt=br.readLine().replaceAll("  "," ");
            String[] s = tt.split(" ");
            int n = Integer.parseInt(s[0]);
            int m = Integer.parseInt(s[1]);
            if (n == 0 && m == 0)
                break;
            init();
            System.out.println(count(m) - count(n - 1));
        }
    }

    private static void init() {
        dp = new int[11][10];
        for (int i = 0; i < 10; i++) {
            if (i == 4)
                dp[1][4] = 0;
            else
                dp[1][i] = 1;
        }
        for (int i = 2; i < 11; i++) {
            for (int j = 0; j < 10; j++) {
                for (int k = 0; k < 10; k++) {
                    if ((j != 4 && k != 4))
                        dp[i][j] += dp[i - 1][k];
                    if (j == 6 && k == 2)
                        dp[i][j] -= dp[i - 1][k];
                }
            }
        }
    }

    private static int count(int x) {
        if (x == 0)
            return 1;
        List<Integer> list = new ArrayList<>();
        while (x > 0) {
            list.add(x % 10);
            x /= 10;
        }
        int ans = 0;
        int last = 0;
        for (int i = list.size() - 1; i >= 0; i--) {
            int t = list.get(i);
            if (last == 4)
                break;
            for (int j = 0; j < t; j++) {
                if (j == 4 || (last == 6 && j == 2))
                    continue;
                ans += dp[i + 1][j];
            }
            if (t == 4 || (t == 2 && last == 6))
                break;
            last = t;
            if (i == 0)
                ans++;
        }
        return ans;
    }
}