#include <bits/stdc++.h>

#define ll long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second

using namespace std;

int i, j, nr, n;

bool prime(int x)
{
	for (int i = 2; i * i <= x; i++)
		if (x % i == 0)
			return 0;
	return 1;
}

int main()
{
	// freopen("test.in", "r", stdin);
	// freopen("test.out", "w", stdout);

	scanf("%d", &n);
	if (n <= 10)
	{
		nr = 1;
		for (j = 2; j < n; j++)
			nr = (nr * j) % n;
		printf("%d\n", nr);
	}
	else
	{
		if (prime(n))
			printf("%d\n", n - 1);
		else
			printf("0\n");
	}

	return 0;
}