description: Luntik came out for a morning stroll and found an array a of length n. He calculated the sum s of the elements of the array (s= ∑_{i=1}^{n} a_i). Luntik calls a subsequence of the array a nearly full if the sum of the numbers in that subsequence is equal to s-1.
  
  Luntik really wants to know the number of nearly full subsequences of the array a. But he needs to come home so he asks you to solve that problem!
  
  A sequence x is a subsequence of a sequence y if x can be obtained from y by deletion of several (possibly, zero or all) elements.
  
  Input
  
  The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases. The next 2 ⋅ t lines contain descriptions of test cases. The description of each test case consists of two lines.
  
  The first line of each test case contains a single integer n (1 ≤ n ≤ 60) — the length of the array.
  
  The second line contains n integers a_1, a_2, …, a_n (0 ≤ a_i ≤ 10^9) — the elements of the array a.
  
  Output
  
  For each test case print the number of nearly full subsequences of the array.
  
  Example
  
  Input
  
  
  5
  5
  1 2 3 4 5
  2
  1000 1000
  2
  1 0
  5
  3 0 2 1 1
  5
  2 1 0 3 0
  
  
  Output
  
  
  1
  0
  2
  4
  4
  
  Note
  
  In the first test case, s=1+2+3+4+5=15, only (2,3,4,5) is a nearly full subsequence among all subsequences, the sum in it is equal to 2+3+4+5=14=15-1.
  
  In the second test case, there are no nearly full subsequences.
  
  In the third test case, s=1+0=1, the nearly full subsequences are (0) and () (the sum of an empty subsequence is 0).
solution: /*
      @@     @@    @@@@@@@@@    @@      @    @       @         @@@@@@@@@    @       @    @@@@@@@@@       @
      @ @   @ @    @       @    @ @     @    @       @         @       @    @       @    @       @      @@
      @  @ @  @    @       @    @  @    @    @       @         @       @    @       @    @       @    @@ @
      @   @   @    @       @    @   @   @    @       @         @@@@@@@@@    @@@@@@@@@    @       @       @  
      @       @    @       @    @    @  @    @       @                 @            @    @       @       @
      @       @    @       @    @     @ @    @       @                 @            @    @       @       @
      @       @    @@@@@@@@@    @      @@    @@@@@@@@@         @@@@@@@@@            @    @@@@@@@@@    @@@@@@@
  */
   
  import java.util.*;
  import java.io.*;
  import java.math.*;
  public class codeforces
  {
       // File Input/Output
       
       /*public static void main(String args[])throws IOException
       {
            File file = new File("input.txt");
            Scanner sc = new Scanner(file);
            FileWriter fw = new FileWriter("output.txt");
            fw.write("___");
            fw.close();
       }*/
       
       
       // Standard Input/Output
       
       public static void main(String args[])
       {
           Scanner sc=new Scanner(System.in);
           int t=sc.nextInt();
           while(t-- > 0)
           {
                int n=sc.nextInt();
                int arr[]=new int[n];
                int i,c0=0,c1=0;
                for(i=0;i<n;i++)
                {
                     arr[i]=sc.nextInt();
                     if(arr[i]==0)
                     c0++;
                     if(arr[i]==1)
                     c1++;
                }
                if(c1==0)
                System.out.println("0");
                else
                {
                     long x = (long)(Math.pow(2,c0));
                     x = x*(long)c1;
                     System.out.println(x);
                }
           }
       }
  }