#include <bits/stdc++.h>

using namespace std;

int n, m;
bool vis[15];

int main(){
	cin >> n >> m;
	
	int cnt = 0;
	for (int i = n; i <= m; i ++ ){
		vis[0] = vis[1] = vis[2] = vis[3] = vis[4] = vis[5] = vis[6] = vis[7] = vis[8] = vis[9] = false;
		int tmp = i, len = 0;
		while (tmp){
			len ++;
			tmp /= 10;
		}
		
		bool flag = true;
		tmp = i;
		while (tmp){
			if (vis[tmp % 10] || tmp % 10 >= len){
				flag = false;
				break;
			}
			vis[tmp %10] = true;
			tmp /= 10;
		}
		
		if (flag){
			cnt ++;
		}
	}
	
	cout << cnt;
	return 0;
}