979A - Pizza Pizza Pizza - CodeForces Solution

/*

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   |oooooooo|OOOOOOOOOOo.\ \     / /oOOOOOOOOOOOo [ -Tim Park ] |.:@#|
*/

  
#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
// #include <ext/rope>
#define int ll
#define mp        make_pair
#define pb        push_back
#define all(a)      (a).begin(), (a).end()
#define sz(a)      (int)a.size()
#define eq(a, b)       (fabs(a - b) < EPS)
#define md(a, b)    ((a) % b + b) % b
#define mod(a)      md(a, MOD)
#define _max(a, b) ((a) > (b) ? (a) : (b))
#define srt(a)      sort(all(a))
#define mem(a, h)    memset(a, (h), sizeof(a))
#define f         first
#define s         second
#define forn(i, n)      for(int i = 0; i < n; i++)
#define fore(i, b, e)  for(int i = b; i < e; i++)
#define forg(i, b, e, m)  for(int i = b; i < e; i+=m)
#define index  int mid = (b + e) / 2, l = node * 2 + 1, r = l + 1;
#define DBG(x) cerr<<#x<<" = "<<(x)<<endl
#define RAYA cout<<"=============================="<<'\n'
// int in(){int r=0,c;for(c=getchar();c<=32;c=getchar());if(c=='-') return -in();for(;c>32;r=(r<<1)+(r<<3)+c-'0',c=getchar());return r;}
 
 
using namespace std;
// using namespace __gnu_pbds;
// using namespace __gnu_cxx;
 
// #pragma GCC target ("avx2")
// #pragma GCC optimization ("O3")
// #pragma GCC optimization ("unroll-loops")
 
typedef long long     ll;
typedef long double ld;
typedef unsigned long long     ull;
typedef pair<int, int>  ii;
typedef pair<pair<int, int>, int> iii;
typedef vector<int>     vi;
typedef vector<ii>      vii;
typedef vector<ll>      vll;
// typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
// find_by_order kth largest  order_of_key <
// mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// rng
const int tam = 200010;
const int MOD = 1000000007;
const int MOD1 = 998244353;
const double DINF=1e100;
const double EPS = 1e-9;
const long double PI  = acos(-1.0L);
 
 


signed main()
{
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    // freopen("asd.txt", "r", stdin);
    // freopen("qwe.txt", "w", stdout);
    int n;
    cin>>n;
    n++;
    if(n==1){
        cout<<0<<'\n';
        return 0;
    }
    if(n%2==0){
        cout<<n/2<<'\n';
        return 0;
    }
    cout << n << '\n';
    
 
    
    
 
 
    return 0;
}