#include<bits/stdc++.h>
using namespace std;
int a,b,ans,x,r[8],i,c,s=1;
int main(){
	cin>>a>>b;
	for(i=a;i<=b;i++){
		x=i;
		i=s;
		while(x!=0){
			r[s]=x%10;
			x=x/10;
			s++;
		}
		for(int j=1;j<=s+1;j++){
		    max(r+1,r+s+1);
		    if(r[s]!=s-j+1){
		    	break;
			}
			r[s]=true;
		}
		ans++;
	}
	cout<<ans<<endl;
	return 0;
}