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.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class A
{
	public static void main(String[] args) throws IOException
	{
		Scanner sc = new Scanner(System.in);
		PrintWriter pw = new PrintWriter(System.out);
		
		int n = sc.nextInt();
		int[] arr = new int[n];
		boolean[] sq = new boolean[10000000];
		for(int i = 0; i < 1005; i++)
		{
			sq[i*i] = true;
		}

		int max = -10000000;
		for(int i = 0; i < n; i++)
		{
			arr[i] = sc.nextInt();
			if(arr[i] < 0)
			{
				max = Math.max(max, arr[i]);
			}
			else
			if(!sq[arr[i]])
				max = Math.max(max, arr[i]);
		}

		pw.println(max);
		
		pw.flush();
		pw.close();
	}
	static class Scanner
	{
		StringTokenizer st;
		BufferedReader br;

		public Scanner(InputStream s)
		{
			br = new BufferedReader(new InputStreamReader(s));
		}

		public Scanner(String s) throws FileNotFoundException
		{
			br = new BufferedReader(new FileReader(new File((s))));
		}

		public String next() throws IOException
		{
			while (st == null || !st.hasMoreTokens())
				st = new StringTokenizer(br.readLine());
			return st.nextToken();
		}

		public int nextInt() throws IOException
		{
			return Integer.parseInt(next());
		}

		public long nextLong() throws IOException
		{
			return Long.parseLong(next());
		}

		public String nextLine() throws IOException
		{
			return br.readLine();
		}

		public double nextDouble() throws IOException
		{
			String x = next();
			StringBuilder sb = new StringBuilder("0");
			double res = 0, f = 1;
			boolean dec = false, neg = false;
			int start = 0;
			if (x.charAt(0) == '-')
			{
				neg = true;
				start++;
			}
			for (int i = start; i < x.length(); i++)
				if (x.charAt(i) == '.')
				{
					res = Long.parseLong(sb.toString());
					sb = new StringBuilder("0");
					dec = true;
				} else
				{
					sb.append(x.charAt(i));
					if (dec)
						f *= 10;
				}
			res += Long.parseLong(sb.toString()) / f;
			return res * (neg ? -1 : 1);
		}

		public boolean ready() throws IOException
		{
			return br.ready();
		}
	}
}
