#include <iostream>
#include <fstream>

using namespace std;

ifstream fin("fractii.in");
ofstream fout("fractii.out");
int cmmdc(int a, int b)
{
    while(a!=b)
    {
        if(a>b)
            a=a-b;
        else
            b=b-a;
    }
    return a;
}



int main()
{
    int n;
    fin>>n;
    long long k=2*n-1;

    for(int i=2;i<=n;i=i+2)
    {
        for(int j=3;j<=n;j=j+2)
        {
            if(cmmdc(i,j)==1)
                k++;
        }
    }

    for(int i=3;i<=n;i=i+2)
    {
        for(int j=2;j<=n;j=j+2)
        {
             if(cmmdc(i,j)==1)
                k++;
        }
    }
    fout<<k;
    return 0;
}