#include <bits/stdc++.h>
using namespace std;
#define FAST ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define pb push_back
#define fixx(n) fixed << setprecision(n)
#define F first
#define S second
#define PI  3.14159265358979323846
#define ll  long long int
#define int ll
#define double long double
const int mod = 1e9 + 7;
const int modd = 998244353;
const int N = 1e5;


signed main()
{

    FAST;
    int n;
    cin >> n;
    if(n % 2) cout << 1;
    else {
        cout << n * (n - 1);
    }
    return 0;
}