#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<n;i++)
#define int long long
static const ll mod=998244353;

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