QuanYeuTruc

#include <iostream>
#include <math.h>

#define ll long long
#define LIM 1000005
#define X first
#define Y second
#define EL cout<<"\n"

using namespace std;

int div_calc(int x)
{
    int res = 0;

    for (int i = 1; i <= sqrt(x); i++)
        if (x % i == 0)
        {
            if (i == sqrt(x)) { res++; continue; }
            res += 2;
        }

    return res;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    
    int n; cin >> n;

    int ans = 0;

    for (int sum1 = 1; sum1 < ceil((float)n / 2); sum1++)
    {
    	int sum2 = n - sum1;

        // cout << sum1 << " : " << sum2 << " | ";

        // cout << div_calc(sum1) << " : " << div_calc(sum2) << endl;

    	ans += div_calc(sum1) * div_calc(sum2);
    } 

    ans *= 2;

    if (n % 2 == 0) ans += div_calc(n / 2) * div_calc(n / 2); 

    cout << ans;

   

    return 0;
}