# include <bits/stdc++.h>
using namespace std;
int n,a[50000005],c[50000005],maxn=5*1e7,res;
bool b[50000005];

void sang()
{
    for (int i = 1; i <= maxn; i++)
    {
        b[i] = true;
        a[i] = i;
    }
    b[1] = false;
    for (int i = 2; i <= sqrt(maxn); i++)
    {
        if (b[i])
        {
            for (int j = i*i; j <= maxn; j+= i)
            {
                b[j] = false;
            }
            for (int j = i*i; j <= maxn; j+=i*i)
            {
                while (a[j] % (i*i) == 0)
                {
                    a[j] /= (i*i);
                }
            }
        }
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n;
    sang();
    for (int i = 1; i <= n; i++)
    {
        c[a[i]]++;
    }
    for (int i = 1; i <= n; i++)
    {
        res += (c[i]*c[i]);
    }
    cout << res;
}