GERGOVIA  Wine trading in Gergovia
Gergovia consists of one street, and every inhabitant of the city is a wine salesman. Everyone buys wine from other inhabitants of the city. Every day each inhabitant decides how much wine he wants to buy or sell. Interestingly, demand and supply is always the same, so that each inhabitant gets what he wants.
There is one problem, however: Transporting wine from one house to another results in work. Since all wines are equally good, the inhabitants of Gergovia don't care which persons they are doing trade with, they are only interested in selling or buying a specific amount of wine.
In this problem you are asked to reconstruct the trading during one day in Gergovia. For simplicity we will assume that the houses are built along a straight line with equal distance between adjacent houses. Transporting one bottle of wine from one house to an adjacent house results in one unit of work.
Input
The input consists of several test cases.
Each test case starts with the number of inhabitants N (2 ≤ N ≤ 100000).
The following line contains n integers a_{i} (1000 ≤ a_{i} ≤ 1000).
If a_{i} ≥ 0, it means that the inhabitant living in the i^{th} house wants to buy a_{i} bottles of wine. If a_{i} < 0, he wants to sell a_{i} bottles of wine.
You may assume that the numbers a_{i} sum up to 0.
The last test case is followed by a line containing 0.
Output
For each test case print the minimum amount of work units needed so that every inhabitant has his demand fulfilled.
Example
Input:
5
5 4 1 3 1
6
1000 1000 1000 1000 1000 1000
0
Output:
9
9000
hide comments
try2catch:
20160207 11:10:46
1st Attempt AC type question ^_'


geoffreymace7:
20151008 19:21:13
Wouldn't have thought of the O(n) solution had I not read the comments...awesome problem! 

Shubham Goyal:
20150929 20:23:59
This can be solved in O(1) space and O(n) time, think greedy ;) =>AC 

shravinson:
20150906 13:32:53
O(n)==> 0.03 sec AC 

SangKuan:
20150824 04:54:59
O(n),common lisp got tle,c use 0.04s 

anando_du:
20150730 09:12:41
easy one ... use long long int


Dikshant Gupta:
20150728 13:25:24
@monkz


monkz:
20150713 09:32:35
is there an O(n) solution? 

Sumit Paroothi:
20150705 04:22:48
easy one....don't think too much! 

Anmol Varshney:
20150701 15:28:30
My 50th :D 
Added by:  HNUE 
Date:  20091030 
Time limit:  0.5s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 NODEJS OBJC PERL6 SQLITE VB.NET 
Resource:  UVA 