#include <iostream>
#include <cstdio>
using namespace std;
int cmmdc(int a,int b)
{
    while(b)
    {
        int r=a%b;
        a=b;
        b=r;
    }
    return a;
}
int main()
{
    freopen("fractii.in","r",stdin);
    freopen("fractii.out","w",stdout);
    int n,i,j,Ans;
    cin>>n;
    Ans=2*n-1;
    for(i=3;i<=n;i++)
        for(j=2;j<i;j++)
            if(cmmdc(i,j)==1)
               Ans+=2;
    cout<<Ans;
    return 0;
}