abc_conjecture

#include<iostream>
#include<cstdlib>

#define long long long
#define nln '\n'

using namespace std;

int main()
{
    //freopen("abc_conjecture.inp", "r", stdin);
    long n;
    cin >> n;
    long ans = 0, co2 = 0, co3 = 0;
    for (long a = 1; a*a*a <= n; ++a)
        for (long b = a; b*b <= n; ++b)
        {
            long c = n/(a*b);
            if (c < b)
                break;
            ans += c-b+1;
        }

    cout << ans << nln;
    return 0;
}