#include <iostream>
#include <fstream>
using namespace std;
int gcd(int a, int b) {
    return b == 0 ? a : gcd(b, a % b);
}
int main()
{
    ifstream cin ("fractii.in");
    ofstream  cout ("fractii.out");
    int n,cnt=0;
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        for(int j=i;j<=n;j++)
        {
            if(gcd(i,j)==1)
                cnt+=2;
        }
    }
    cout<<cnt-1;
    return 0;
}