#include <iostream>
#include <stdio.h>
#include <cstring>


using namespace std;

long long a, b;
int n[10];

bool is_balanced (int x) {
    memset (n, 0, sizeof n);
    while (x) {
        n[x%10]++;
        x /= 10;
    }

    for (int i = 0; i < 10; i++)
        if ((i % 2) == (n[i] % 2) and n[i] != 0)
            return 0;

    return 1;
}
int main () {
    //cin >> a >> b;
    scanf ("%lld %lld", &a, &b);
    long long ans = 0;
    for (long long i = a; i <= b; i++)
        ans += (int)is_balanced (i);
    printf ("%lld\n", ans);
}
