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

vector<int> primes2(int N){
    // returns a list of prime numbers up to N (including N).
    if (N == 1) return vector<int>{};
    if (N == 2) return vector<int>{2};
    if (N <= 4) return vector<int>{2, 3};
    vector<bool> isPrime(N + 1, true);
    for (int p = 5, d = 2; p * p <= N; p += d, d = 6 - d){
        if (isPrime[p]){
            for (int q = p * p, delta = d; q <= N; q += delta * p, delta = 6 - delta){
                isPrime[q] = false;
            }
        }
    }
    vector<int> primes = {2, 3};
    for (int p = 5, d = 2; p <= N; p += d, d = 6 - d){
        if (isPrime[p]) primes.push_back(p);
    }
    return primes;
}

int main(){
    int N;
    cin >> N;
    vector<int> ps = primes2(3 * N);
    vector<int> ds((3 * N)/2 + 1, 0);
    for (auto p : ps) ds[p/2] = 1;
    vector<int> hps;
    for (int i = 1; ps[i] <= N; ++i){
        hps.push_back(ps[i]/2);
    }
    vector<long long> ab(N, 0);
    long long cnt = 0;
    for (int i = 1; i < hps.size(); ++i){
        for (int j = 1; j < hps[i] * 2; ++j){
            if (ab[j] and ds[j + hps[i] + 1]) cnt += ab[j];
        }
        for (int j = 0; j < i; ++j) ab[hps[j] + hps[i]] += 1LL;
    }
    cout << cnt << endl;
    return 0;
}