#include<bits/stdc++.h>
using namespace std;
bool f(int a){
	bool b[10];
	int aa=a,s=0;
	for(int i=0;i<10;i++)b[i]=0;
	while(aa>=1){
		aa/=10;
		s++;
	}
	//cout<<s<<" "<<a<<endl;
	while(a>=1){
		if(b[a%10]==0&&a%10<s)b[a%10]=1;
		else return false;
		a/=10;
	}
	return true;
}
int main(){
	int a,b,ans=0;
	cin>>a>>b;
	for(int i=a;i<=b;i++)if(f(i))ans++;
	cout<<ans;
	return 0;
} 
/*A    FFFFF    OOO
 A A   F       O   O
AAAAA  FFFFF   O   O
A   A  F       O   O
A   A  F        OOO    */