#include<bits/stdc++.h>
using namespace std;
bool check (int n)
{
	int b = 0,x = n;
	while (x != 0)
	{
		b ++;
		x /= 10;
	}
	int g[10];
	memset(g,0,sizeof(g));
	while (n != 0)
	{
		int s = n % 10;
		g[s] ++;
		n /= 10;
	}
	for (int i = 0; i < b; i ++)
	{
		if (g[i] != 1)
		{
			return 0;
		}
	}
	for (int i = 0; i <= 9; i ++)
	{
		if (g[i] > 1)
		{
			return 0;
		}
	}
	return 1;
}
int main(){
	int a,b,r = 0;
	cin >> a >> b;
	for (int j = a; j <= b; j ++)
	{
		if (check(j))
		{
			r ++;
		}
	}
	cout << r;
	return 0;
}