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.


Added by:Efim
Date:2010-11-04
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64

hide comments
2015-12-11 12:48:34
Thank u @Abishek yr suggestion for fast io worked
2015-11-22 18:44:32
use scanf to read values in c++
2015-11-11 16:02:51 sumit suthar
Just XOR... :)
2015-10-28 23:07:32
If using Sort method use Scanf instead of CIN.
2015-10-10 18:14:28 shivam
if using cin or cout,set sync_with_stdio(false);
cin.tie(NULL);
2015-10-07 16:27:05 nap11
is this possible in java?
2015-09-26 18:03:58 DeviSree
same sol TLE in python anyway nice question
2015-09-20 13:17:29 Sarthak Munshi
ridiculous problem statement !
2015-09-19 09:13:49
xor method is easier ....way...
2015-09-18 04:26:54 MSK
did it in java tle :(
same in c ac... Not fair for java...
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