#include <bits/stdc++.h>
using namespace std;
#define rep1(a)          for (int i = 0; i < (a); i++)
#define rep2(i, a)       for (int i = 0; i < (a); i++)
#define rep3(i, a, b)    for (int i = a; i < (b); i++)
#define rep4(i, a, b, c) for (int i = a; i < (b); i += c)
#define overload4(a, b, c, d, e, ...) e
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
using ll = long long;
constexpr ll INF = (1LL << 60);
void chmax(ll& a, ll b) { a = max(a, b);}
void chmin(ll& a, ll b) { a = min(a, b); }
inline void YesNo(bool ok) {
  cout << (ok ? "Yes\n" : "No\n");
}
template<class T>
void input_vec(vector<T>& v) {
  for (auto& x : v) cin >> x;
}
template<class... T>
void input(T&... a) {
  (cin >> ... >> a);
}
void print() {
  cout << '\n';
}
template<class T, class... Ts>
void print(const T& a, const Ts&... b) {
  cout << a;
  (cout << ... << (cout << ' ', b));
  cout << '\n';
}
bool isPrime(int n)
{
    if (n == 1)
        return false; // 1 縺ｯ邏謨ｰ縺ｧ縺ｯ縺ｪ縺・
    for (int i = 2; i <= sqrt(n); i++)
    {
        if (n % i == 0)
            return false;
    }

    return true;
}

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

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int a, b;
  cin >> a >> b;
  int ans = 0;
  for (int i = a; i <= b; i++) {
    if (isPrime(i))ans += f(i);
  }
  cout << ans << endl;
}