#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

inline bool is_prime(int x) {
  for (int i = 2; i * i <= x; ++i) {
    if (x % i == 0) return false;
  }
  return true;
}

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

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int a, b;
  cin >> a >> b;
  int ans = 0;
  for (int x = a; x <= b; ++x)
    if (is_prime(x)) ans += f(x);
  cout << ans << '\n';
  return 0;
}