import java.util.Arrays;
import java.util.LinkedList;
import java.util.Scanner;

public class Main {
	
	public static long MOD = 1000000007;
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final int N = sc.nextInt();
		long[] as = new long[N];
		for(int i = 0; i < N; i++){ as[i] = sc.nextLong(); }
		
		long min = as[0], max = as[0];
		for(int i = 1; i < N; i++){
			long curr_min = min + as[i];
			long curr_max = max + as[i];
			
			// +
			{
				curr_min = Math.min(curr_min, min + as[i]);
				curr_min = Math.min(curr_min, max + as[i]);
				curr_max = Math.max(curr_max, min + as[i]);
				curr_max = Math.max(curr_max, max + as[i]);
			}
			// -
			{
				curr_min = Math.min(curr_min, min - as[i]);
				curr_min = Math.min(curr_min, max - as[i]);
				curr_max = Math.max(curr_max, min - as[i]);
				curr_max = Math.max(curr_max, max - as[i]);
			}
			// *
			{
				curr_min = Math.min(curr_min, min * as[i]);
				curr_min = Math.min(curr_min, max * as[i]);
				curr_max = Math.max(curr_max, min * as[i]);
				curr_max = Math.max(curr_max, max * as[i]);
			}
			
			min = curr_min;
			max = curr_max;
		}
		
		System.out.println(max);
	}
}