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).


First line of input contains number of pyanis N <= 500 000. Next N lines contain a single positive integer 1 <= Pi <= 10^9.


Output one positive integer on pyani, which appeared once.



Output: 8

Onotole has found not optimal AC algorithms, so all solutions will be rejudged. He is watching you.

hide comments
Mohit: 2015-09-16 05:39:29

this question is really taught new thing..

aleksije: 2015-09-11 15:28:53

50th problem :D

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.. :)

Added by:Efim
Time limit:0.134s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64