#include <bits/stdc++.h>

using namespace std;

int f(int x) {
    return x * x * x - x * x + x + 1;
}

int main() {
    int A, B;
    cin >> A >> B;
    int ans = 0;
    for (int i = A; i <= B; i++) {
        bool isPrime = true;
        for (int j = 2; j <= min(7, i - 1); j++) {
            isPrime &= i % j != 0;
        }
        if (isPrime) {
            ans += f(i);
        }
    }
    cout << ans << endl;
    return 0;
}