#include<iostream>
using namespace std;

int main(){
	int left,right,ans=0;
	cin>>left>>right;
	for(int i=left;i<=right;i++){
		int sum[11]={0},t=i,count=0;
		bool flag=true;
		while(t>0){
			sum[t%10]++;
			t/=10;
			count++;
		}
		for(int j=0;j<count;j++){
			if(sum[j]!=1){
				flag=false;
				break;
			}
		}
		if(flag){
			ans++;
		}
	}
	cout<<ans;
	return 0;
}