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

int n, cnt = 0;

signed main() {
    cin >> n;
    for (int i = 1; i * i <= n; i++) {
        int k = i * i;
        for (int j = 1; j * j <= k; j++) {
            if (k % j == 0 && k / j <= n) cnt++;
        }
    }
    cout << cnt;
}