By XI Maratona de Programação IME-USP, 2007 Brasil
The teacher Cris became known as a machiavellian person in your institution. For those not aware of the situation, the teacher required students to form a queue in lexicographical order (by name) with at most k permutations. This meant that many students do not even enter the room to take the test. However, this selective she resolved to redeem himself against students, and decided to apply a little trouble retrieval.
Your task, even if not disapproved, is given a sequence of n integers a1, a2, ..., an. Where -30 ≤ aj ≤ 30 for j = 1, ..., n, print, if there is an integer ak such that . If more than an integer that satisfies this condition, print the first in the sequence.
Note from teacher: "Boys, remember that the sum of any nonzero number is not zero! Okay?"
The entrance is composed of several instances. The first line of each instance consists of an integer; n;(1 ≤ n ≤100) indicating the number of integers in the following line should to be processed. The entry ends with end of file.
For each instance, you must print an identifier "Instancia k", where k is the number of the current instance starting with 1. On the next line print the integer that satisfies the restriction described above. If no such integer exists print "nao achei".
After each instance print a blank line.
|Sample Input||Sample Output|
1 2 3 4 5 6 7
5 20 35