#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main () {
	ll p;
	cin >> p;
	ll ans = 0;
	ll b = p - 1;
	for (ll i = p-1; i >= 0; i --) {
		ans = (ans + b) % p;
		b = (b * i) % p;
	}
	cout << ans << endl;
}