#include<bits/stdc++.h>
using namespace std;
long long a,b,i,k=0,s=0,h=0;;
int x[10];
int main(){
	cin>>a>>b;
	for(i=a;i<=b;i=i*10){
		k++;
		h+=k;
		s+=h;
	}
	cout<<s;
	return 0;
}