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

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int Need = 100;
    vector<bool> prime(Need+1,true);
    prime.at(0) = false; prime.at(1) = false;
    for(int i=2; i*i<=Need; i++){
        if(!prime.at(i)) continue;
        for(int k=i*i; k<=Need; k+=i) prime.at(k) = false;
    }
    int A,B; cin >> A >> B;
    int answer = 0;
    for(int i=A; i<=B; i++) if(prime.at(i)) answer += i*i*i-i*i+i+1;
    cout << answer << endl;
}