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.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.util.StringTokenizer;
import java.lang.Math;
import java.io.*;

public class Main {
/********************************************************************************/
static class FastReader {
BufferedReader br; StringTokenizer st;
public FastReader(){br = new BufferedReader(new InputStreamReader(System.in));}
String next() { while (st == null || !st.hasMoreElements()){
try { st = new StringTokenizer(br.readLine());}
catch (IOException e) { e.printStackTrace();}}
return st.nextToken();} int nextInt(){ return Integer.parseInt(next());}
long nextLong() { return Long.parseLong(next());}
float nextFloat(){return Float.parseFloat(next());}
double nextDouble() { return Double.parseDouble(next());}
String nextLine() { String str = ""; try { str = br.readLine();}
catch (IOException e) { e.printStackTrace(); } return str;}
}
/*******************************************************************************/
public static void main(String[] args) {
FastReader sc = new FastReader();
int n = sc.nextInt();
int[] arr = new int[n];
for(int i = 0;i<n;i++){
    arr[i] = sc.nextInt();
}
Arrays.sort(arr);
for(int i = n-1;i>=0;i--){
    int a = (int)(Math.sqrt(arr[i]));
    if(arr[i] != a*a){
        System.out.println(arr[i]);
        break;
    }
}
}
}
