OLOLO - Onotole needs your help


Onotole has a lot of pyani. Each pyani has a number, writing on it. Pyanis with equal numbers are indistinguishable. Onotole knows everything, so, he knows that each pyani appeared twice, and only one pyani is unique. He wants to get вздръжни эффект, and he needs the unique pyani. Given the list of pyanis denote which one of them appeared once (it is guaranteed that other pyanis appeared twice).

Input

First line of input contains number of pyanis N <= 500 000. Next N lines contain a single positive integer 1 <= Pi <= 10^9.

Output

Output one positive integer on pyani, which appeared once.

Example

Input:
3
1
8
1

Output: 8

Onotole has found not optimal AC algorithms, so all solutions will be rejudged. He is watching you.


hide comments
[Mayank Pratap]: 2015-05-06 18:27:41

Its good to make progress day by day,learning new things ........Meanwhile I was wondering what Mitch and Francky are talking about :P

Kishore H Patel: 2015-04-16 19:49:21

For JAVA user's "chully bhar pani mein doob maro" => It's not your cup of tea

Prasanna Patil: 2015-04-14 04:04:39

Nice problem...
Learnt something awesome.

bholagabbar: 2015-04-13 21:43:29

Alright so this code in almost impossible to solve in the given constraints in java. Atleast by the method i used to solve it in C++ with fast IO (http://codeforces.com/blog/entry/6251). I got TLE without the thing mentioned in the link and AC with it.

As for JAVA, i tried picking up uwi's IO and implementing it in mine and running. Still TLE. If not uwi's IO then umm...you've got a major probelm. For those who don't know uwi:

www.codechef.com/users/uwi

Last edit: 2015-04-13 22:10:59
arjun: 2015-04-13 17:28:20

Whatever language you use. Just perform faster io operations.
Can be done in O(n) and O(nlogn) too.

MD: 2015-04-02 21:53:39

great concept!! new thing to learn..

Last edit: 2015-04-02 21:54:31
.:: Jarv1s ::.: 2015-03-15 19:06:30

Learned a new thing!

Francky: 2015-02-03 19:08:28

The issue seems solved.


Added by:Efim
Date:2010-11-04
Time limit:0.134s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64