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
karthik1997: 2018-01-05 15:51:16

Man , int and xor are enough ! O(1) space is enough !

amankumarjha: 2018-01-01 11:27:01

Taught me to use xor and %llu

bani_raheja: 2017-12-29 16:07:26

what is the point of having such problems if you want people to use Fast I/O? :3

sai__teja_01: 2017-11-29 19:29:18

easy problem ,if ur facing TLE use scanf and printf instead cin and cout ,if ur using c++

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);


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