#include<bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i = (a); i <= (b); ++i)
#define FORD(i,a,b) for(int i = (a); i >= (b); --i)
#define RI(i,n) FOR(i,1,(n))
#define REP(i,n) FOR(i,0,(n)-1)
#define mini(a,b) a=min(a,b)
#define maxi(a,b) a=max(a,b)
#define mp make_pair
#define pb push_back
#define st first
#define nd second
#define sz(w) (int) w.size()
typedef vector<int> vi;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int inf = 1e9 + 5;
const int nax = 1e6 + 5;

int f(int n) {
	int r = 1;
	RI(i, n - 1) r = (ll) r * i % n;
	return r;
}

int main() {
	int n;
	scanf("%d", &n);
	if(n <= 10) printf("%d\n", f(n));
	else {
		for(int a = 2; a * a <= n; ++a)
			if(n % a == 0) {
				puts("0");
				return 0;
			}
		printf("%d\n", n - 1);
	}
	return 0;
}