博弈论×贪如心√

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
int a[100005];
int main(){
    int n;
    cin >> n;
    for(int i = 1; i <= n; i++) cin >> a[i];
    sort(a + 1, a + n + 1, greater <int>());
    int ct1 = 0, ct2 = 0;
    for(int i = 1; i <= n; i += 2){
        ct1 += a[i], ct2 += a[i + 1];
    }
    cout << abs(ct1 - ct2);

	return 0;
}