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 bisearch(f, n):
    l = 0
    r = n
    fl = f(l)
    fr = f(r)
    while l <= r:
        m = (l + r) // 2
        fm = f(m)
        #print l,m,r,fl,fm,fr,n
        if fm == n:
            return m
        elif fm > n:
            r = m - 1
            fr = f(r)
        else:
            l = m + 1
            fl = f(l)

def try_square_root(n2):
    return bisearch(lambda n:n*n, n2)

N = int(input())
A = input().split()

for i in range(N):
    A[i] = int(A[i])

A.sort(reverse=True)

for i in range(N):
    if try_square_root(A[i]) == None:
        print(A[i])
        quit()
