#include <bits/stdc++.h>
using namespace std;
#define int long long

int A,B;

signed main(){
  cin>>A>>B;
  int ans = 0;
  for(int i = A; i <= B; i++){
  	int cnt = 0;
  	for(int j = 1; j <= i; j++){
  		if(i % j == 0) cnt++;
  	}
  	if(cnt == 2){
  		ans += (i*i*i) - (i*i) + (i) + 1;
  	}
  }
  cout << ans << "\n";
}