//#include <cstdio>
#define max_n 1000000 
#include <fstream>

using namespace std;

int n;
int sum[max_n];
long long sol;

void tera(){
    int i,j;
    for(i=1;i<=n;i++)
         sum[i]=i-1;
    for(i=2;i<=n;i++)
       {
          for(j=(i<<1);j<=n;j+=i)sum[j]=sum[j]-sum[i];
          sol+=sum[i];
       }
}

int main(void){
     //freopen("fractii.in", "r", stdin);
     //freopen("fractii.out", "w", stdout);
     //scanf("%d",&n);
     ifstream i("fractii.in");
     ofstream o("fractii.out");
     i>>n;
     sol=0;
     tera();
     
     //printf("%d",((sol<<1)|1));   
     o<<((sol<<1)|1);
}