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
Prakhar Dev Gupta: 2015-09-11 11:01:05

1 1 2 3 4 will fetch what output and y?

Abishek: 2015-09-09 13:45:20

fast i/o needed . cost me two TLEs ..

sneh sajal: 2015-08-30 16:50:47

use scanf and think mathematically :)

jack_jay: 2015-08-25 13:44:19

easy.......taught me use of XOR.....and no use of long long in c++ 5.1.//

gaurav117: 2015-08-24 22:19:39

@poojan use fast i/p o/p in C to get less time

poojan : 2015-08-23 04:55:01

done with xor still tacking time!0.15 how can i do it batter!

Harsh Vardhan Ladha: 2015-08-16 07:00:26

use long long
and yeah scanf and printf are faster than cin and cout, so use scanf & printf, even with xor technique

prakash_reddy: 2015-08-09 08:56:35

Use ios_base::sync_with_stdio(0); and scanf and printf for faster input and output.. :)

MishThi: 2015-08-04 11:05:03

1. Really good question. Taught me about the XOR operator.. :D
2. Same solution gave AC in "C" but TLE in "Python 2.7.10" :(

Akshay Aradhya: 2015-07-18 22:38:58

@Arnab Fast I/O Not required in C++


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