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.
from sys import stdin, stdout
import math
from itertools import permutations, combinations
from collections import defaultdict
from bisect import bisect_left 

mod = 1000000007

def L():
	return list(map(int, stdin.readline().split()))

def In():
	return map(int, stdin.readline().split())

def I():
	return int(stdin.readline())

def printIn(ob):
	return stdout.write(str(ob)+'\n')

def powerLL(n, p):
	result = 1
	while (p):
		if (p&1):
			result = result * n % mod
		p = int(p / 2)
		n = n * n % mod
	return result

#--------------------------------------

def myCode():
    a = I()
    lst1 = L()
    lst1.sort()
    for i in range(a-1,-1,-1):
        if str(lst1[i]**0.5)[-1]=='0':
            continue
        else:
            print(lst1[i])
            exit()
def main():
	# for t in range(I()):
		myCode()
if __name__ == '__main__':
    # print(math.sqrt(4))
    main()