#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <set>

using namespace std ;

/*ifstream cin ("input") ;
ofstream cout ("output") ;*/

int nr = 0 ; 
void backt (long long number, long long b, long long a) {
	if (number >= b) return ; 
	if (number == 0) -- nr;
	++ nr ; 
	for (int i = (int)a; i <= 9 ; ++ i) {
		backt (number * 10LL + i, b, a) ; 
	}
}

int main(int argc, char const *argv[])
{
	long long a, b ;
	cin >> a >> b ; 
	if (a >= 10) {
		cout << 0 ;
		return 0 ; 
	}
	backt (0, b, a) ; 
	cout << nr ; 
	return 0;
}