#include <iostream>
#include <cstdio>
#include <numeric>
#include <algorithm>
#include <string>
#include <vector>
#include <functional>
#include <cmath>
#include <queue>
#include <set>

#define rep(i, a) FOR(i, 0, a)
#define FOR(i, a, b) for(int i = a; i < b; ++i)

typedef long long ll;
typedef unsigned long long ull;
typedef std::pair<int, int> P;
typedef std::pair<P, int> PP;
struct edge{ int to, time, cost; };

const double esp = 1e-9;
const int max = (int)1e+5 + 10;

int n;
int main(){
	std::cin >> n;
	if (n % 2 == 0)std::cout << n / 2 << std::endl;
	else std::cout << n << std::endl;
	return 0;
}