#include <iostream>
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
ll a, b, cnt;
bool vis[1000020] = {};

bool check(ll x) {
	memset(vis, 0, sizeof(vis));
	ll j = 1, dig;
	for (ll i = 10; i <= 10000000; i *= 10) {
		if (x < i) {
			dig = j;
			break;
		}
		j++;
	}
	while (x > 0) {
		if (x % 10 >= dig) return 0;
		if (vis[x % 10] == 1) return 0;
		vis[x % 10] = 1;
		x /= 10;
	}
	return 1;
}

int main() {
	cin >> a >> b;
	for (ll i = a; i <= b; i++) {
		if (check(i)) cnt++;
	}
	cout << cnt;
	return 0;
}