#include <bits/stdc++.h>
using namespace std;
bool check (int x)
{
	int flag[10];
	memset (flag, 0, sizeof (flag));
	int cnt = 0;
	while (x)
	{
		++cnt;
		int dw = x % 10;
		++flag[dw];
		x /= 10;
	}
	for (int i = 0;i < cnt;i++)
	{
		if (flag[i] != 1)
		{
			return false;
		}
	 }
	return true;
}
int main()
{
	int a, b;
	cin >> a >> b;
	int ans = 0;
	for (int i = a;i <= b;i++)
	{
		if (check (i))
		{
			++ans;
		}
	}
	cout << ans;
	return 0;
}