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.ArrayList;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.PriorityQueue;
  import java.util.Queue;
  import java.util.StringTokenizer;
  
  
  import java.io.*;
   
  public class cf745 {
  	
  	private static class MyScanner {
  	    BufferedReader br;
  	    StringTokenizer st;
   
  	    public MyScanner() {
  	       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());
  	    }
   
  	    double nextDouble() {
  	        return Double.parseDouble(next());
  	    }
   
  	    String nextLine(){
  	        String str = "";
  		  try {
  		     str = br.readLine();
  		  } catch (IOException e) {
  		     e.printStackTrace();
  		  }
  		  return str;
  	    }
   
  	 }
  
  	public static long solution(int n, int[] arr)	
  	{
  		int z = 0;
  		int o = 0;
  		
  		for(int i = 0; i<n; i++)
  		{
  		   if(arr[i]==0)
  			   z++;
  		   if(arr[i]==1)
  			   o++;		
  		}
  		
  		long k = (long)Math.pow(2,z);
  		return o*k;
  	}
  	
  	
  private static PrintWriter out = new PrintWriter(System.out);
   
  public static void main (String[] args)
  {
  	MyScanner s =  new MyScanner();
      
  	int t = s.nextInt();
  	
  	while(t-->0)
      {
  		int n = s.nextInt();
  		int[] arr = new int[n];
  		
  		for(int i = 0; i<n; i++)
  			arr[i] = s.nextInt();
   		
          out.println(solution(n,arr));
      }
       
      out.flush();
      out.close();
  }
  }