#include <bits/stdc++.h>

using namespace std;

ifstream in("fractii.in");
ofstream out("fractii.out");

bool prim(int a,int b)
{
    int c;
    while(b>0)
    {
        c=b;
        b=a%b;
        a=c;
    }
    if(a==1)
        return 1;
    return 0;
}

int main()
{
    int n,i,j;
    long long s;
    in>>n;
    s=2*n-1;
    for(i=2;i<=n;i++)
        for(j=i+1;j<=n;j++)
            if(prim(i,j)==1)
                s=s+2;
    out<<s;
    return 0;
}