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

int a, b, ans;

bool check(int x){
	int num = 0;
	int p[10] = {0};
	while(x > 0){
		int t = x % 10;
		p[t]++;
		x /= 10;
		num++;
	}
	for(int i = 0;i < num;i++){
		if(p[i] != 1) return false;
	}
	return true;
}

int main(){
	cin >> a >> b;
	for(int i = a;i <= b;i++){
		if(check(i)){
			ans++;
		}
	}
	cout << ans << "\n";
	return 0;
}