/* * @Date : 2021-06-13 23:59:15 * @Author : ssyze * @Description : */ #include<bits/stdc++.h> using namespace std; #ifndef ONLINE_JUDGE #define dbg(x...) do { cout << "\033[32;1m " << #x << " -> "; err(x); } while (0) void err() { cout << "\033[39;0m" << endl; } template<template<typename...> class T, typename t, typename... A> void err(T<t> a, A... x) { for (auto v: a) cout << v << ' '; err(x...); } template<typename T, typename... A> void err(T a, A... x) { cout << a << ' '; err(x...); } #else #define dbg(...) #endif typedef long long ll; typedef pair<int,int> pi; typedef vector<int> vi; template<class T> using vc=vector<T>; template<class T> using vvc=vc<vc<T>>; template<class T> void mkuni(vector<T>&v) { sort(v.begin(),v.end()); v.erase(unique(v.begin(),v.end()),v.end()); } ll rand_int(ll l, ll r) { static mt19937_64 gen(chrono::steady_clock::now().time_since_epoch().count()); return uniform_int_distribution<ll>(l, r)(gen); } template<class T> void print(T x,int suc=1) { cout<<x; if(suc==1) cout<<'\n'; else cout<<' '; } template<class T> void print(const vector<T>&v,int suc=1) { for(int i=0;i<v.size();i++) print(v[i],i==(int)(v.size())-1?suc:2); } int n; int main() { ios::sync_with_stdio(0); cin.tie(0); cin >> n; vi a(n); for (auto &x: a) cin >> x; sort(a.begin(), a.end()); ll ans = LONG_LONG_MIN, aa = 0, bb = 0; for (int i = 0; i < n; i++) { if (i & 1) bb += a[i]; else aa += a[i]; } ans = max(ans, abs(aa)-abs(bb)); aa = 0, bb = 0; reverse(a.begin(), a.end()); for (int i = 0; i < n; i++) { if (i & 1) bb += a[i]; else aa += a[i]; } ans = max(ans, abs(aa)-abs(bb)); cout << ans << '\n'; }