#include <iostream>
#include <vector>
using namespace std;

int main() {
	int N, ans = 0;
	cin >> N;
	vector<bool> a(N + 1, true);
	a[0] = a[1] = false;
	for (int i = 2; i * i <= N; ++i) {
		if (a[i]) {
			for (int j = 2 * i; j <= N; j += i) a[j] = false;
		}
	}
	for (int i = 2; i * i <= N; ++i) {
		for (int j = 2; j < i * i - 1; ++j) {
			if (a[i] && a[i * i - j] && a[j]) ++ans;
		}
	}
	cout << ans;
}