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.
n = int(raw_input())
l = raw_input().split()
l = [int(x) for x in l]

maxnum = -10000000

def perfect_square(n):
    x = n // 2
    y = set([x])
    while x * x != n:
        x = (x + (n // x)) // 2
        if x in y: return False
        y.add(x)
    return True

for num in l:
    if num >= 0:
        if num != 0 and num != 1:
            if perfect_square(num) == False:
                if num > maxnum:
                    maxnum = num
    else:
        if num > maxnum:
            maxnum = num

print maxnum