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.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.*;
  import java.util.Queue;
  import java.util.LinkedList;
  import java.util.StringTokenizer;
  import java.lang.Math;
  import java.io.*;
  
  public class Main {
  /********************************************************************************/
    public static class FastReader {
      BufferedReader br; StringTokenizer st;
      public FastReader(){br = new BufferedReader(new InputStreamReader(System.in));}
      String next() { while (st == null || !st.hasMoreElements()){
      try { st = new StringTokenizer(br.readLine());}
      catch (IOException e) { e.printStackTrace();}}
      return st.nextToken();} int nextInt(){ return Integer.parseInt(next());}
      long nextLong() { return Long.parseLong(next());}
      float nextFloat(){return Float.parseFloat(next());}
      double nextDouble() { return Double.parseDouble(next());}
      String nextLine() { String str = ""; try { str = br.readLine();}
      catch (IOException e) { e.printStackTrace(); } return str;}
    }
  /*******************************************************************************/
    public static void main(String[] args){
      FastReader sc = new FastReader();
      int t = sc.nextInt();
      while(t-->0){
          int n = sc.nextInt();
          int[] arr = new int[n];
          long s = 0;
          for(int i = 0;i<n;i++){
              arr[i] = sc.nextInt();
              s += arr[i];
          }
          long count1 = 0 ;
          long count2 = 0;
          long d = s-1;
          for(int i = 0;i<n;i++){
              if(arr[i] == 0)
                  count1++;
              if(arr[i] == 1)
                  count2++;
          }
          if(count2==0){
  			System.out.println(0);
  		}
  		else{
  			long ans = (long) Math.pow(2, count1);
  			ans = ans*(long)count2;
  			System.out.println(ans);
  		}
      }
    }
  }
  
  
  