CANDY - Candy I

Jennifer is a teacher in the first year of a primary school. She has gone for a trip with her class today. She has taken a packet of candies for each child. Unfortunately, the sizes of the packets are not the same.

Jennifer is afraid that each child will want to have the biggest packet of candies and this will lead to quarrels or even fights among children. She wants to avoid this. Therefore, she has decided to open all the packets, count the candies in each packet and move some candies from bigger packets to smaller ones so that each packet will contain the same number of candies. The question is how many candies she has to move.

Input specification

The input file consists of several blocks of data. Each block starts with the number of candy packets N (1<= N <=10000) followed by N integers (each less than 1000) in separate lines, giving the number of candies in each packet. After the last block of data there is the number -1.

Output specification

The output file should contain one line with the smallest number of moves for each block of data. One move consists of taking one candy from a packet and putting it into another one. If it is not possible to have the same number of candies in each packet, output the number -1.

Example

Input file:
5
1
1
1
1
6
2
3
4
-1

Output file:
4
-1

Added by:Fudan University Problem Setters
Date:2007-12-01
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: C99 ERL JS-RHINO
Resource:IPSC 1999

hide comments
2018-01-26 19:44:59
what if this is the test case
2
4
4
-1
what will be the output?
2018-01-21 22:46:55
misread problem, woops
2017-10-22 06:47:44
can we use arrays for this
2017-08-31 03:58:06
AC in one go (: easy af
2017-08-25 08:34:54
@shubham9261 simple sum/n
2017-08-15 06:57:22
if i modify the question and ask you to print the value of each packet after equalizing it??? how eill you do it??
2017-08-14 07:26:49

Ac in one Go:) feeling happy
2017-07-31 13:22:46
AC in one go!!!!
2017-07-15 13:12:46
I cant understand the sample test case. When N=5 then why there are more than 5 integers beneath?
2017-06-25 00:19:43 YeisonEduardo
wrong answer =( why?
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