#include<bits/stdc++.h>
#include <atcoder/all>
#ifdef LOCAL
#include <debug_print.hpp>
#define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (static_cast<void>(0))
#endif
using namespace atcoder;
using mint=modint998244353;
using namespace std;
using ll=long long;
using ul=unsigned long long;
int dx[9] = {-1, 1, 0, 0, -1, -1, 1, 1, 0};
int dy[9] = {0, 0, -1, 1, -1, 1, -1, 1, 0};
using Graph=vector<vector<int>>;
ll op(ll a,ll b){return min(a,b);}
ll e(){return 2e9;}
vector<pair<int,char>>RLE(string S){
    vector<pair<int,char>>ans;
    int cnt=0;
    char c=S[0];
    for(int i=0;i<S.size();i++){
        if(S[i]==c)cnt++;
        else ans.push_back({c,cnt}),cnt=1,c=S[i];
      }
    ans.push_back({c,cnt});
    return ans;
}
int main(){
	ll N;
	cin>>N;
	cout<<(N/2+1)*((N+1)/2+1)-1<<endl;
}