# -*- coding: utf-8 -*-
amountOfStones = int(input())
stones = [int(i) for i in input().split()]
stones.sort(reverse=True)
first = [stones[0]]
second = []
i = 1
while i < len(stones):
    if sum(first) > sum(second):
        second.append(stones[i])
    else:
        first.append(stones[i])
    i += 1
print(abs(sum(first) - sum(second)))