#include<iostream>
#include<stdio.h>
using namespace std;
FILE *f,*g;
int i,n,a[1000001],j;
long long nr;
int main()
{
    f=fopen("fractii.in","r");
    g=fopen("fractii.out","w");
    fscanf(f,"%d",&n);
    for(i=1;i<=n;i++)
        a[i]=i-1;
    for(i=2;i<=n;i++)
        for(j=i+i;j<=n;j=j+i)
          a[j]=a[j]-a[i];
    for(j=2;j<=n;j++)
       nr=nr+a[j];
       cout<<nr<<endl;
        fprintf(g,"%lld",nr*2+1);
}