#include <fstream>
#include <math.h>

using namespace std;

bool prime_intre(int a, int b)
{
	while(a != b)
	{
		if(a > b) a -= b;
		else b -= a;
	}
	return (a == 1);
}

int indicatorEuler(int x)
{
	int answer = 1;
	int d = 2, p = 0;
	while(x != 1)
	{
		if(!(x%d)) p++;
		else
		{
			answer *= (d-1)*pow(d, p-1);
			x /= pow(d, p);
			p = 0;
			d++;
		}
	}
	return answer;
}

int main() {
	ifstream in("fractii.in");
	ofstream out("fractii.out");
	int n, output = 1;
	in >> n;
	int i, j, aux;
	out << indicatorEuler(2);

	for(i = 2; i <= n; i++)
	{
		// aux = 0;
		// for(j = 1; j < i; j++)
		// {
		// 	aux += prime_intre(i,j);
		// }
		// aux = indicatorEuler(i);
		// output += 2*aux;
	}
	out << output << endl;

}