#include<bits/stdc++.h>
using namespace std;
int n,m;
int s=0,n1,m1;
int k[10];
int check(int x,int y){
	memset(k,0,sizeof(k));
	while(x>0){	
	 	int z=x%10;
		k[z]+=1;
		x/=10;
	}
	for(int i=0;i<y;i++){
		 if(k[i]==0 || k[i]>1){
		 	return 1;
		 }
	}
	return 0;
}
int main(){
	cin>>n>>m;
	for(int i=n;i<=m;i++){
		int s1=0;
		if(i>=1 && i<=9){
			s1=1;
		}if(i>=10 && i<=99){
			s1=2;
		}if(i>=100 && i<=999){
			s1=3;
		}if(i>=1000 && i<=9999){
			s1=4;
		}if(i>=10000 && i<=99999){
			s1=5;
		}if(i>=100000 && i<=999999){
			s1=6;
		}if(i==1000000){
			s1=7;
		}
		if(check(i,s1)==0){
			s+=1;
		}
	}cout<<s;
	return 0;
}