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
rohitkr2997: 2016-12-29 14:06:25

ios_base::sync_with_stdio (false);cin.tie(0); as first statement of main function. Use property of x^x=0 and x^0=x.

hasan356: 2016-12-28 07:12:40

AC in one go!!Use Xor

rakeshgupta: 2016-12-17 13:37:45

Last edit: 2016-12-18 08:27:15
julkas: 2016-12-17 10:22:58

Last edit: 2017-03-05 15:32:46
apurvgs: 2016-12-14 06:48:33

cin and cout gives TLE
use scanf and printf
very easy using bitmap

rakeshgupta: 2016-12-13 11:33:09

@julkas what is "and ... 5 L. BR.??". Sorry, but i am a beginner in python, so not so well in acronyms (if it is one).

Last edit: 2016-12-13 11:37:24
julkas: 2016-12-06 09:24:29

One pass. O(N).

asgupta_spoj: 2016-12-03 20:14:53

easy question
just took o(logn+n) time complexity

julkas: 2016-12-03 16:11:06


Last edit: 2017-03-05 15:33:36
rakeshgupta: 2016-12-01 17:42:27

Last edit: 2016-12-13 11:37:49

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