백준(java)약수 - 1037

 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		int N = Integer.parseInt(st.nextToken());
		int result = 0;
		int[]arr = new int[N];
		st = new StringTokenizer(br.readLine());
		for(int i=0;i<arr.length;i++) {
			arr[i] = Integer.parseInt(st.nextToken());
		}
		Arrays.sort(arr);
		if(N==1) {
			result = arr[0]*arr[0];
		}else {
			result = arr[0]*arr[N-1];
		}
		System.out.println(result);
	}
}