#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <complex>

using namespace std;

#define REP(i,n)	for(int i=0;i<(n);++i)
#define REPS(i,s,t)	for(int i=(s);i<(t);++i)

#define INF 		2000000007
#define MOD			1000000007

#define MAX 		200005

typedef unsigned int 			uint;
typedef unsigned long long int	ull;
typedef long long int 			ll;

//int dp[MAX];


int main(){
	int N;cin>>N;

	if(N%2==1){
		cout << N << endl;
		return 0;
	}
	int a;
	a = N/2;
	cout << a << endl;
	

	return 0;
}