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.
arr = [i**2 for i in xrange(10**3+1, -1, -1)]
n = input()
inp = sorted(map(int, raw_input().strip().split()))[::-1]
p1 = 0
p2 = 0
while p2<n:
    if inp[p2]<0:
        print inp[p2]
        break
    elif arr[p1]>inp[p2]:
        p1+=1
    elif arr[p1]==inp[p2]:
        p2+=1
    else:
        print inp[p2]
        break