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.

a=int(input())
b=input()
b=b.split(' ')
s=[]
for i in range(len(b)):
    if int(b[i])>=0:
        b[i]=int(b[i])
        f=b[i]
        b[i]=b[i]**0.5
        if b[i]!=int(b[i]):
            b[i]=int(b[i])
            s.append(f)
    else:
        s.append(int(b[i]))
    
print(max(s))
