#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a,b,s=0;
	cin>>a>>b;
	for(int i=a;i<=b;i++){
		int arr[100]={0},flag=1,w=0;
		for(int j=1;j<=i;j*=10){
			w++;
		}
		for(int j=1;j<=i;j*=10){
			if(i/j%10<w&&arr[i/j%10]==0){
				arr[i/j%10]=1;
			}
			else{
				flag=0;
				break;
			}
		}
		if(flag){
			s+=1;
		}
	}
	cout<<s;
	return 0;
}