Given an array a1, a2, ..., an of n integers, find the largest number in the array that is not a perfect square.

A number x is said to be a perfect square if there exists an integer y such that x = y2.

Input

The first line contains a single integer n (1 ≤ n ≤ 1000) — the number of elements in the array.

The second line contains n integers a1, a2, ..., an ( - 106 ≤ ai ≤ 106) — the elements of the array.

It is guaranteed that at least one element of the array is not a perfect square.

Output

Print the largest number in the array which is not a perfect square. It is guaranteed that an answer always exists.

Examples

Input

2
4 2


Output

2


Input

8
1 2 4 8 16 32 64 576


Output

32

Note

In the first sample case, 4 is a perfect square, so the largest number in the array that is not a perfect square is 2.
import sys
import math

#read in information from std input
ls = []
answer = -1

####################################################
# When submitting for real, comment the next line,
# uncomment when developing.
#sys.stdin = open("../input/input1")
####################################################

els = sys.stdin.readline().strip()

for i in sys.stdin.readline().split(' '):
    num = int(i.strip())
    if num < 0:
        ls.append(num)
    else:
        rt = int(math.ceil(math.sqrt(num)))
        if rt*rt != num:
            ls.append(num)

ls.sort()
answer = ls[-1]

print answer
