#include<stdio.h>
int k,N;
void citire()
{ FILE *f=fopen("fractii.in","r");
  fscanf(f,"%d",&N);
  fclose(f);
}

int prim(int a,int b)
{ int d,l,ok=1;
  if(a>b) l=b;
  else l=a;
  for(d=2;d<=l;d++)
     if(a%d==0 && b%d==0) ok=0;
  if(ok==0) return 0;
  else return 1;
}
void prelucrare()
{ int i,j;
  for(i=1;i<=N;i++)
     for(j=i;j<N;j++)
	if(prim(i,j)==1) k=k+2;
  FILE *g=fopen("fractii.out","w");
  fprintf(g,"%d",k);
  fclose(g);
}
int main()
{ citire();
  prelucrare();
  return 0;
}