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.*;
import java.util.*;
import java.util.stream.IntStream;

public class A764 {
    public static void main(String [] args) {
        InputStream inputReader = System.in;
        OutputStream outputReader = System.out;
        InputReader in = new InputReader(inputReader);
        PrintWriter out = new PrintWriter(outputReader);
        Algorithm solver = new Algorithm();
        solver.solve(in, out);
        out.close();
    }
}

class Algorithm {
    void solve(InputReader ir, PrintWriter pw) {
        int n = ir.nextInt();
        int [] num = new int[n];
        int max = 0;

        for (int i = 0; i < n; i++) num[i] = ir.nextInt();
        Qsort(num, 0, n - 1);

        for (int i = n - 1; i >= 0; i--) {
            if (num[i] >= 0) {
                double sqrt = Math.sqrt(num[i]);
                int x = (int) sqrt;
                if (Math.pow(sqrt, 2) != Math.pow(x, 2)) {
                    max = num[i];
                    break;
                }
            } else {
                max = num[i];
                break;
            }

        }

        pw.print(max);

    }

    private static void Qsort(int[] array, int low, int high) {

        int i = low;
        int j = high;
        int x = array[low + (high - low) / 2];

        do {
            while (array[i] < x) ++i;
            while (array[j] > x) --j;
            if (i <= j) {
                int tmp = array[i];
                array[i] = array[j];
                array[j] = tmp;
                i++;
                j--;
            }
        } while (i <= j);

        if (low < j) Qsort(array, low, j);
        if (i < high) Qsort(array, i, high);

    }
}

class InputReader {
    private BufferedReader reader;
    private StringTokenizer tokenizer;

    InputReader(InputStream stream) {
        reader = new BufferedReader(new InputStreamReader(stream), 32768);
        tokenizer = null;
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    int nextInt() {
        return Integer.parseInt(next());
    }
    double nextDouble() {
        return Double.parseDouble(next());
    }
    long nextLong() {
        return Long.parseLong(next());
    }

}