#include <iostream>
using namespace std;
int cmmdc (int a,int b)
{
    int t;
    while(b)
    {
        t=a%b;
        a=b;
        b=t;
    }
    return a;
}
int main (void)
{
    int n,s=0,i,j;
    cin>>n;
    s=n*2-1;
    for(i=2;i<n;i++)
        for(j=i+1;j<=n;j++)
            if(cmmdc(i,j)==1)
                s=s+2;
    cout<<s;
    return 0;
}