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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int a, b;
    cin >> a >> b;
    ll ans = 0;
    vector<bool> tb(200);
    for(int i = 2; i <= 200; i++){
        if(tb[i]) continue;
        if(a <= i && i <= b){
            ans += i * i * i - i * i + i + 1;
        }
        for(int j = 2 * i; j <= 200; j += i) tb[j] = true;
    }
    cout << ans << '\n';
}