#include <stdio.h>

long n, maxF;

void citire() {
  freopen("fractii.in", "r", stdin);

  scanf("%ld", &n);
  fclose(stdin);
}

int cmmdc(long a, long b) {
  int r;

  while(b) {
    r = a%b;
    a = b;
    b = r;
  }

  return a;
}

int main() {
 freopen("fractii.out", "w", stdout);

 citire();

 long i, j, max;

 maxF = 2*n-1;

 for(i=2; i<=n; i++){
  max = 0;

  for(j=i+1; j<=n; j++)
    if(cmmdc(i,j) == 1)
      max+=2;

  maxF += max;
 }

 printf("%d\n", maxF);

 fclose(stdout);
 return 0;
}