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.
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.StringTokenizer;

public class A {

	public static void main(String[] args) throws Exception {
		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw = new PrintWriter(System.out);
		StringTokenizer st;
		int n = Integer.parseInt(bf.readLine());
		HashSet<Long> per = new HashSet<>();
		st = new StringTokenizer(bf.readLine());
		long[] arr = new long[n];
		for (int i = 0; i < arr.length; i++) {
			arr[i] = Long.parseLong(st.nextToken());
		}
		for (int i = 0; i <= 1000; i++) {
			per.add((long)Math.pow(i, 2));
		}
		long max = -1000000000;
		for (int i = 0; i < arr.length; i++) {
			if(!per.contains(arr[i]))
				max = Math.max(max, arr[i]);
		}
		pw.println(max);
		pw.close();
	}
}