#include <fstream>
using namespace std;
  
int Cmmdc ( int i, int j);

int main()   
{   
    int n, i, j = 0, numar = 0;   
  
    ifstream fin("fractii.in");   
    fin >> n;   
    fin.close();   
  
    for ( i = 1; i <= n ; i++)   
           if ( Cmmdc( i, j++) == 1)
                        numar++;  
    ofstream fout("fractii.out");   
    fout << numar;   
    fout.close();   
    return 0;   
}  


 int Cmmdc(int i, int j)
{
    int rest;
    do
    {
        rest = i % j;
        i = j;
        j = rest;
    } while ( rest );
    
    return i;
}