#include <fstream>
#include <cstdlib>

using namespace std;

int main(){
	fstream fin("fractii.in"),fout("fractii.out");
	char *a; int n,i,j,s=0;
	fin>>n;
	a=(char*)malloc((n+1)*(n+1)*sizeof(char));
	for(i=1;i<=n;i++)for(j=1;j<=n;j++)a[n*i+j]=0;
	for(i=1;i<=n;i++)
		for(j=1;j<=n;j++)
			if(a[n*i+j]==0){
				s++;
				for(int k=1;i*k<=n && j*k<=n;k++)a[i*k*n+j*k]=1;
			}
	fout<<s;
	fin.close();
	fout.close();
	return 0;
}