#include<iostream>
#include<fstream>
using namespace std;
int cmmdc(int x,int y)
{
    while(x!=y) if(x>y) x=x-y;
    else y=y-x;
    return x;
}
int main()
{
    int n,i,j,nr=0;
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    f>>n;
    for(i=1;i<=n-1;i++)
    for(j=i+1;j<=n;j++)
    if(cmmdc(i,j)==1) nr=nr+2;
    g<<nr+1;
    f.close();
    g.close();
    return 0;
}