#include <fstream>
using namespace std;

int main()
{
    ifstream fin ("fractii.in");
    ofstream fout ("fractii.out");
    int N , Q  , P;
    fin>>N;
    int nr = N, i;
    int nr_ir = 1 ; //Presupun ca nr sunt IReductibile
        for ( P = 2 ; P <= N ; ++P )
        {
            for ( Q = 1 ; Q <= N ; ++Q )
            {
                for ( i = 2 ; i <= 1000000 ; ++i )
                {
                    if ( (P % i == 0 && Q % i == 0) || P == Q){
                        nr_ir = 0;
                        goto final;
                        }
                    else
                        nr_ir=1;
                }
final:
                if ( nr_ir == 1)
                    ++nr;
            }
        }
        fout<<nr;
        return 0;
}