#include <cstdio>
#define max_n 1000000 

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);
     sol=0;
     tera();
     
     printf("%d",((sol<<1)|1));   
}