#include <iostream>
#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int ireductibil(int p,int q)
{
    int r=p%q;
    while(r)
    {
        p=q;
        q=r;
        r=p%q;
    }
    return q;
}
int main()
{
    int n,cnt;
    f>>n; cnt=2*(n-1)+1;
    for(int i=2;i<=n-1;i++)
        for(int j=i+1;j<=n;j++)
            //if((i%2!=0)||(j%2!=0))
                if(ireductibil(i,j)==1) cnt+=2;
    g<<cnt;
    f.close();
    g.close();
    return 0;
}