#include <iostream>
#include <fstream.h>

using namespace std;

int PrimeNum(int m,int n){
   if (n==0) return m;
  else return PrimeNum(n, m%n);
}  
int n,i,j,c;

int main(){
 ofstream outputFile; 
 outputFile.open("fractii.out");  
 fstream file_op("fractii.in",ios::in);
 file_op>>n;
 file_op.close();
 for(i=2;i<=n;i++)
 for(j=1;j<=i-1;j++) if(!((i%2==0)&&(j%2==0))) if (PrimeNum(i,j)==1) c=c+2;
outputFile<<c+1<<endl; 
outputFile.close();
//system("Pause");
return 0;
}