#include <bits/stdc++.h>
#define REP(i, a, n) for(ll i = ((ll) a); i < ((ll) n); i++)
using namespace std;
typedef long long ll;
ll MOD = 1e9 + 7;
ll odd = 0;
ll even = 0;

ll Rec(ll n) {
    if (n == 1) return 1;
    else if (n%2 == 0) {
        odd += Rec(n-1);
        return n * odd;
    }
    else {
        even += Rec(n-1);
        return n * even;
    }
}

int main(void) {
    int n;
    cin >> n;
    cout << Rec(n) << endl;
    return 0;
}