#include<bits/stdc++.h>
using namespace std;

#define int long long
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,a,b) for(int i=(a);i<(b);i++)
#define pb push_back
#define all(v) (v).begin(),(v).end()

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

    if(N&1)cout<<N<<endl;
    else cout<<N/2<<endl;
    return 0;
}