#include<bits/stdc++.h>
using namespace std;
int stnum,finum,ans,len;
bool check(int x){
	bool f[10]={0,0,0,0,0,0,0,0,0,0};
	int t=x;
	while(t){
		if(t%10>=len||f[t%10])return 0;
		f[t%10]=1;
		t/=10;
	}
	return 1;
}
int main(){
	cin>>stnum>>finum;
	for(int i=stnum;i<=finum;i++){
		len=(log10(i))+1;
		if(check(i)){
			ans++;
		}
	}
	cout<<ans;
	return 0;
}