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

class Sieve {
private:
  vector<bool> is_pr;
  vector<int> pr;
public:
  Sieve(int n) : is_pr(n + 1, true) {
    if (0 < n + 1) is_pr.at(0) = false;
    if (1 < n + 1) is_pr.at(1) = false;
    for (int i = 2; i * i <= n; i++) {
      if (!is_pr.at(i)) continue;
      for (int j = i * i; j <= n; j += i) is_pr.at(j) = false;
    }
    for (int i = 2; i < n + 1; i++) {
      if (is_pr.at(i)) pr.push_back(i);
    }
  }
  vector<bool> getB() { return is_pr; }
  vector<int> getP() { return pr; }
};

int main() {
  int N;
  cin >> N;
  Sieve S(N * 3);
  auto P = S.getP();
  long ans = 0;
  vector<int> cnt(N * 3 + 1);
  for (int c = 0; c < P.size(); c++) {
    if (P.at(c) > N) break;
    for (int n = c + 1; n < P.size(); n++) {
      ans += cnt.at(P.at(n) - P.at(c));
    }
    int b = c;
    for (int a = 0; a < b; a++) {
      cnt.at(P.at(a) + P.at(b))++;
    }
  }
  cout << ans << "\n";
}