#include <bits/stdc++.h>
using namespace std;
int main(){
	int a,b;
	cin>>a>>b;
	int cntt=0;
	for (int i=a;i<=b;i++){
		int t=i;
		int c=0;
		while (t!=0){
			c++;
			t/=10;
		}
		int count[c+1];
		int k=i;
		int cc=0;
		while (k!=0){
			int newn=k%10;
			cc+=1;
			count[cc]=newn;
			k/=10;
		}
		bool flag=true;
		sort(count+1,count+c+1);
		for (int j=0;j<c;j++){
			if (j==count[j+1]){
				continue;
			}
			else {
				flag=false;
				break;
			}
		}
		if (flag==true){
			cntt+=1;
		}
	}
	cout<<cntt;
}