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
Arnab Mitra: 2015-05-20 22:31:10

In case you are doing this question using a sort, please use fast I/O

[Mayank Pratap]: 2015-05-06 18:27:41

Its good to make progress day by day,learning new things ........Meanwhile I was wondering what Mitch and Francky are talking about :P

Kishore H Patel: 2015-04-16 19:49:21

For JAVA user's "chully bhar pani mein doob maro" => It's not your cup of tea

Prasanna Patil: 2015-04-14 04:04:39

Nice problem...
Learnt something awesome.

bholagabbar: 2015-04-13 21:43:29

Alright so this code in almost impossible to solve in the given constraints in java. Atleast by the method i used to solve it in C++ with fast IO (http://codeforces.com/blog/entry/6251). I got TLE without the thing mentioned in the link and AC with it.

As for JAVA, i tried picking up uwi's IO and implementing it in mine and running. Still TLE. If not uwi's IO then umm...you've got a major probelm. For those who don't know uwi:


Last edit: 2015-04-13 22:10:59

Added by:Efim
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64