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.
def check(p, a):
    return p ** 2 >= a


def binSearch(a):
    if a < 0:
        return -1

    left, right = -1, a + 1

    while right - left > 1:
        mid = (left + right) // 2

        if check(mid, a):
            right = mid

        else:
            left = mid

    return right


def is_square(x):
    b = binSearch(x)

    return b != -1 and b ** 2 == x


n = int(input())
a = list(map(int, input().split()))

print(max(i for i in a if not is_square(i)))
