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

/// INPUT / OUTPUT
ifstream fin("fractii.in");
ofstream fout("fractii.out");

/// GLOBAL VARIABLES
int n;

/// SOLUTION
inline void solve()
{
    int cnt = 1;
    for(int i = 1; i < n; ++ i)
    {
        for(int j = i + 1; j <= n; ++ j)
        {
            if(__gcd(i, j) == 1)
                cnt+=2;
        }
    }
    fout << cnt;
}

/// READING THE INPUT
int main()
{
    ios::sync_with_stdio(false);
    fin.tie(NULL);
    fout.tie(NULL);
    fin >> n;
    solve();
}