#include <iostream>

using namespace std;

int GCD(int A, int B)
{
    if(B == 0)
        return A;
    return GCD(B, A%B);
}

int main()
{
    int contor = 0;
    int N;

    cout << "N=";
    cin >> N;
    int i = 1 , j = 1;
    while( i <= N && j <= N)
        {
           int cmmdc = GCD(i,j);
           if(cmmdc == 1)
           {
            contor++;
        }
        j++;

        if(j > N)
        {
            j = 1;
            i++;
        }
        }

    cout << contor;
    return 0;
}