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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskA solver = new TaskA();
		solver.solve(1, in, out);
		out.close();
	}

	static class TaskA {
		public void solve(int testNumber, InputReader in, PrintWriter out) {
			int n = in.nextInt();
			int res = Integer.MIN_VALUE;
			for (int i = 0; i < n; i++) {
				int x = in.nextInt();
				if (x < 0) {
					res = Math.max(res, x);
				} else {
					int y = (int) Math.sqrt(x);
					if (y * y != x) {
						res = Math.max(res, x);
					}
				}
			}

			out.println(res);
		}

	}

	static class InputReader {
		final InputStream is;
		final byte[] buf = new byte[1024];
		int pos;
		int size;

		public InputReader(InputStream is) {
			this.is = is;
		}

		public int nextInt() {
			int c = read();
			while (isWhitespace(c))
				c = read();
			int sign = 1;
			if (c == '-') {
				sign = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res = res * 10 + c - '0';
				c = read();
			} while (!isWhitespace(c));
			return res * sign;
		}

		int read() {
			if (size == -1)
				throw new InputMismatchException();
			if (pos >= size) {
				pos = 0;
				try {
					size = is.read(buf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (size <= 0)
					return -1;
			}
			return buf[pos++] & 255;
		}

		static boolean isWhitespace(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}

	}
}

