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.
'''
    http://codeforces.com/problemset/problem/914/A
'''

len_of_values = int(input())
values = list(map(int, input().split(' ')))

def get_square(values):
    maximum = -1000000
    for value in values:
        # print(value, (abs(value**(1/2)))%2)
        if value < 0 and (abs(value**(1/2)) % 2) != 0.0 and maximum < value:
                maximum = value
        elif value > 0 and (abs(value**(1/2)) % 1) != 0.0 and maximum < value:
            maximum = value
    return maximum

print(get_square(values))

# 4 2
# 1 2 4 8 16 32 64 576
# -1 -4 -9
# 994009 992109

# wrong answer 1st numbers differ - expected: '992109', found: '994009'