#include <bits/stdc++.h>
#include "testlib.h"
using namespace std;
using ll = long long;
const ll MIN_N = 1;
const ll MAX_N = 1'000'000'000'000'000'000;

int main(){
	registerValidation();
	ll N = inf.readLong(MIN_N, MAX_N);
	ensure(N % 2 == 0);
	inf.readEoln();
	inf.readEof();
}