#include<stdio.h>

int main()
{FILE *f,*g;
f=fopen("fractii.in","rt");
g=fopen("fractii.out","wt");

long int N,provizoriu,total,i=1,d;
int t;
fscanf(f,"%li",&N);
total=N;

for(i=2;i<=N;i++)
  {provizoriu=0;
  d=2;
  t=0;
  while(d<=i/2)
    {if(i%d==0 && t==1)
      provizoriu=provizoriu-i/d+1;
    if(i%d==0 && t==0)
      {provizoriu=N-i/d+1;
      t=1;
      }
    d++;
    }
  if(t!=0)
    total=total+provizoriu-N/i-1;
  else
    total=total+N-N/i;
  }
fprintf(g,"%li",total);

fclose(f);
fclose(g);
return 0;
}