#include<fstream.h>
long long a[200];
int main(){
ifstream fin("fractii.in");
ofstream fout("fractii.out");
long long N;
fin>>N;
long long nr=N;
for (long long i=2;i<=N;i++){
for (long t=0;t<=N;t++)
    a[t]=0;
	  long long x=i;
	  while (x%2==0){
		a[i]++;
		x/=2;}
	      for (long long h=3;h<=N;h+=2)
		   while (x%h==0){
			 a[h]++;
			 x/=h;}
	    nr++;
	    for (long long e=2;e<=N;e++) {
		short ok=1;
		for (long s=1;s<N;s++)
		   if (a[s]!=0)
		    if (e%s==0)
			ok=0;
		    else
		       if (s%e==0)
			   ok=0;
		if (ok==1)
		   nr++;}
	 }
fout<<nr;
fin.close();
fout.close();
return 0;}