#include <bits/stdc++.h>
using namespace std;
int a, b, cnt, c, d, w, k;
bool vis[15];
void dfs (int step, int s, int jsq){
	if (step == jsq && s >= a && s <= b){
		cnt++;
		return;
	}
	if (s > b){
		printf ("%d", cnt);
		exit(1);
	}
	for (int i = 0; i < jsq; i++){
		if ((s == 0 && i == 0) || vis[i] == 1) continue;
		vis[i] = 1;
		dfs(step + 1, s * 10 + i, jsq);
		vis[i] = 0;
	}
}
int main (){
	scanf ("%d%d", &a, &b);
	c = a, d = b;
	while (c != 0) c /= 10, w++;
	while (d != 0) d /= 10, k++;
	for (int i = w; i <= k; i++)
		dfs (0, 0, i);
	return 0;
}