ac

import java.util.Scanner;


public class Main {

    public static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        int n = sc.nextInt();
        double[] arr = new double[n];
        for(int i=0;i<n;i++){
            arr[i] = sc.nextDouble();
        }
        double res = 0;
        double preMin = 0;
        double preMax = 0;
        res = arr[0];
        preMin = arr[0];
        preMax = arr[0];
        for(int i=1;i<n;i++){
            double tmpMin = preMin;
            double tmpMax = preMax;

            preMin = Math.min(tmpMin * arr[i], tmpMax * arr[i]);
            preMin = Math.min(preMin, arr[i]);

            preMax = Math.max(tmpMax * arr[i], tmpMin * arr[i]);
            preMax = Math.max(preMax, arr[i]);

            res = Math.max(res, preMax);
        }
        System.out.print(String.format("%.2f", res));
    }

}
/*
7
-2.5 4 0 3 0.5 8 -1

12.00
 */