#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int n,nr;

int cmmdc(int x,int y){
  while(x!=y)
  {
      if(x>y)
      x=x-y;
      if(y>x)
      y=y-x;
  }
  return x;
}


int main()
{
    fin>>n;
    for(int i=1;i<=n;i++)
        for(int j=i+1;j<=n;j++)
         if(cmmdc(i,j)==1)
            nr++;

   fout<<nr*2+1;

    return 0;
}