#include<iostream>
#include<fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int prim(long long n, long long m)
{
    long long r;
    while(m != 0)
    {
        long long  r = n % m;
        n = m;
        m = r;
    }
    return n;
}
int main()
{
    long long n;
    f >> n;
    long long c=0;
    for (long long i=1; i<=n; i++)
    {
        long long j=1,ok=0;
        while(ok==0)
        {
            if(prim(i,j)==1)
                    c++;
                    j++;
                    if(j==n+1)
                        ok=1;
            }
}
    g<<c;
}