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
Santosh Kumar Shaw: 2016-04-07 15:46:32

Done using only XOR operator.

aboalmanal2000: 2016-03-31 17:22:00

easy with sorting

nonushikhar: 2016-03-23 15:54:44

simple sort method accepted :|

syed_tanveer: 2016-02-22 16:49:44

cout and cin gave a TLE . :/

abc_c: 2016-02-07 08:14:18

Amazing!!
Didn't know about use of XOR this way.

hamcom1212: 2016-01-26 07:15:01

I used hash map in c++ but get TLE .. :(

prateekmathur1991: 2016-01-12 11:34:50

Got AC with Java... :) Needs fast I/O though...

dokz: 2016-01-06 10:25:01

The problem seems to be impossible in C# \ Java.

sarthak_8: 2016-01-02 20:19:44

Why did not anybody do it with C++ Maps?

Timmy Jose: 2015-12-12 16:05:59

For people using C++ streams, try setting ios_base::sync_with_stdio(false) in your program before doing any input operations. This should help.


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