CF946A Partition

You are given a sequence $ a $ consisting of $ n $ integers. You may partition this sequence into two sequences $ b $ and $ c $ in such a way that every element belongs exactly to one of these sequences. Let $ B $ be the sum of elements belonging to $ b $ , and $ C $ be the sum of elements belonging to $ c $ (if some of these sequences is empty, then its sum is $ 0 $ ). What is the maximum possible value of $ B-C $ ?

The first line contains one integer $ n $ ( $ 1

Print the maximum possible value of $ B-C $ , where $ B $ is the sum of elements of sequence $ b $ , and $ C $ is the sum of elements of sequence $ c $ .

In the first example we may choose $ b={1,0} $ , $ c={-2} $ . Then $ B=1 $ , $ C=-2 $ , $ B-C=3 $ . In the second example we choose $ b={16,23,16,15,42,8} $ , $ c={} $ (an empty sequence). Then $ B=120 $ , $ C=0 $ , $ B-C=120 $ .