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
hitesh87: 2017-10-05 22:42:39

Learned to use xor.AC in many goes;p

vishesh197: 2017-09-23 17:22:15

just use xor as x^x=0 and x^0=x

frobenius: 2017-08-16 20:04:11

Unlike most other problems, do not put a newline at the end of your answer... it will count as wrong.

bhawna_123: 2017-07-04 07:56:34

For a=a^t ,it is giving segmentation fault if i take 'a' as an integer.Could anybody explain me why this is happening

ramesh_961: 2017-06-03 20:18:42

Use printf or scanf if you use c++ instead of cin and cout to avoid TLE!!

shauryauppal: 2017-06-02 14:00:48

use scanf or printf

or
fastIO lines
ios_base::sync_with_stdio(0);cin.tie(NULL);

ayushgupta1997: 2017-05-28 11:00:10

EAsy man took the mistook array size as 10^5 instead of 5*10^5 costed me sigsev...use xor basics :)

sagnik_66: 2017-05-21 08:09:59

Easy!

anurag_tangri: 2017-03-25 17:46:01

CAKEWALK :)

ameyanator: 2017-03-20 06:23:42

Great problem to learn the xor gate!! :')


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