#include <iostream>
#include <cstring>
using namespace std;

#define int long long

int f[10];

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

signed main()
{
	int a,b,cnt = 0;
	cin >> a >> b;
	for (int i = a; i <= b; i++)
	{
		memset(f,0,sizeof(f));
		if (check(i))
		{
			cnt++;
		}
	}
	cout << cnt;
 	return 0;
}