BAEKJOON_1037

import java.io.*;
import java.sql.Array;
import java.util.*;
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        int N = Integer.parseInt(br.readLine());

        int[] arr1 = new int[N];
        int[] arr2 = new int[N];

        StringTokenizer st = new StringTokenizer(br.readLine());
        for(int i=0; i<N; i++){
            arr1[i] = Integer.parseInt(st.nextToken());
        }
        Arrays.sort(arr1);
        long result=0;
        if(arr1.length==1){
            result = (long)Math.pow(arr1[0], 2);

        }
        if(arr1.length >=2){
            if(arr1.length %2!=0){
                result=(long)Math.pow(arr1[arr1.length/2],2);
            }else{
                result = arr1[0] * arr1[N-1];
            }
        }
        bw.write(String.valueOf(result));
        bw.flush();
        bw.close();

        //System.out.println(Math.pow(3,2));

    }
}