#include <bits/stdc++.h>
#include <atcoder/all>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace atcoder;
using namespace __gnu_pbds;
using ll=long long;
using ld=long double;
using vll=vector<ll>;
using vvll=vector<vll>;
using pll=pair<ll,ll>;

// using mint=modint;

// template<class K,class V>
// using ordered_map=tree<K,V,less<K>,rb_tree_tag,tree_order_statistics_node_update>;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

    ll N;
    cin>>N;
    cout<<(N/2+1)*((N+1)/2+1)-1<<endl;

}