#include <iostream>
using namespace std;

int main() {
    int n;
    cin >> n;
    int count = 0;

    for (int x = 1; x <= n; x++) {
        for (int y = x + 1; y <= n; y++) {
            int sum = x + y;
            if (sum % 3 == 0 || sum % 7 == 0) {
                count++;
            }
        }
    }

    cout << count << endl;
    return 0;
}
/**************************************************************
	Problem: 1086
	User: fandaohan
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/