#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

typedef long long LL;

const int N = 100000;

int n, freq[3 * N + 10], ma;
LL ans;
vector<int> primes;
bool is_prime[3 * N + 10];

void SievePrime() {
    fill(is_prime, is_prime + N + 1, true);
    is_prime[0] = is_prime[1] = false;
    for (int i = 2; i <= 3 * N; ++i) {
        if (is_prime[i]) primes.push_back(i);
        for (auto p : primes) {
            if (1LL * i * p > N) continue;
            is_prime[i * p] = false;
            if (i % p == 0) break;
        }
    }
}

int main() {
    SievePrime();

    scanf("%d", &n);

    ans = 0LL;

    for (int i = 2; i < primes.size() && primes[i] <= n; ++i) {
        int c = primes[i];
        int b = primes[i - 1]; // b更小的前面已经构造过了
        for (int j = 0; j < i - 1; ++j) {
            int a = primes[j];
            ++freq[a + b];
        }
        for (int j = 0; j < primes.size(); ++j) {
            int sum = primes[j];
            if (sum - c >= 0) {
                ans += freq[sum - c];
            }
        }
    }
    printf("%lld\n", ans);

    return 0;
}