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

using ll = long long;
using P = pair<ll, ll>;
const ll INF = (1LL << 61);
ll mod = 998244353;

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	ll N; cin >> N;
	vector<ll>c(N); for (int i = 0; i < N; i++)cin >> c[i];
	sort(c.begin(), c.end());
	if (N % 2 == 0) {
		ll a = 0, b = 0;
		for (int i = 0; i < N; i++) {
			if (i % 2 == 0) {
				a += c[i];
			}
			else b += c[i];
		}
		cout << max(abs(a),abs(b)) - min(abs(a), abs(b)) << endl;
	}
	else {
		ll a = 0, b = 0;
		for (int i = 0; i < N; i++) {
			if (i % 2 == 0)a += c[i];
			else b += c[i];
		}
		
		cout << abs(a) - abs(b) << endl;
	}
	return 0;
}