import java.util.*;

public class Main {
    public static Scanner sc = new Scanner(System.in);
    public static int n;
    public static int[] a;
    public static int[] b;
    public static long ret = Long.MIN_VALUE;
    public static void main(String[] args) throws Exception {
        n = sc.nextInt();
        a = new int[n];
        b = new int[n];
        for (int i = 0;i < n;i++) a[i] = sc.nextInt();
        calc(0, a[0]);
        System.out.println(ret);
    }
    
    public static void calc(int c, long val) {
        if (c==n-1) {
            ret = Math.max(ret,val);
            return;
        }
        for (int i = 0;i < 3;i++) {
            if (i==0) calc(c+1,val+a[c+1]);
            if (i==1) calc(c+1,val-a[c+1]);
            if (i==2) calc(c+1,val*a[c+1]);
        }
    }
}