while

#include<bits/stdc++.h>//submitRecord//
using namespace std;
//const int N=1e7+10;
int main(){
//freopen("","r",stdin);
//freopen("","w",stdout);
ios::sync_with_stdio();
cin.tie(nullptr);
cout.tie(nullptr);
int a,b,sum=0,p;
cin >> a >> b;
for(int i=a;i<=b;i++){
p=i;
while(p>0){
sum+=p%10;
p/=10;
}
}
cout<<sum;
//fclose(stdin);
//fclose(stdout);
return 0;
}