#include <iostream>
#include <algorithm>
using namespace std;


#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)

typedef long long ll;
typedef unsigned long long ull;
typedef long double lb;
/* ここからが本編 */


int main(void)
{
   ull i=1,j,k;
   int n;
   int x;
   char cnt = 0;
   cin >> n;
   if( n % 2) x = n;
   else x = n/2;
   cout << x << endl;
   return 0;
}