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

int main() {
	int n;
	cin >> n;
	vector<int> c(n);
	for (int i = 0; i < n; i++){
		cin >> c[i];
	}
	sort(c.begin(), c.end());
	long long a = accumulate(c.begin() + n / 2, c.end(), 0LL);
	long long b = accumulate(c.begin(), c.begin() + n / 2, 0LL);
	cout << abs(abs(a) - abs(b)) << endl;
}