#include <bits/stdc++.h>
using namespace std;
int l[10];
int p=0;
int main(){
    int a,b,ans=0;
	cin>>a>>b;
	for (int i=a;i<=b;i++){
		int s=i;
		int l[10]={0,0,0,0,0,0,0,0,0,0};
        int p=0;
	    while (s!=0){
		    p++;
		    l[s%10]++;
		    s/=10;
	    }
		int flag=0;
		for (int j=0;j<p;j++){
			if (l[j]==1)flag++;
		}
		if (flag==p)ans++;
	} 
	cout<<ans<<endl;
	return 0;
}