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:   /* package codechef; // don't place package name! */
  import java.util.*;
  import java.lang.*;
  import java.io.*;
  import java.math.BigInteger;
  
  
  
  public class hello
  {
     static class Pair{
      int i=0;
      int j=0;
      int d=0;
      public Pair(int i,int j,int d)
      {
          this.i=i;
          this.j=j;
          this.d=d;
      }
  }
       
  
       static class FastReader 
      { 
          BufferedReader br; 
          StringTokenizer st; 
    
          public FastReader() 
          { 
              try {
                 br=new BufferedReader(new FileReader("input.txt"));
                 PrintStream out= new PrintStream(new FileOutputStream("output.txt"));
                 System.setOut(out);
              }
    
              // Catch block to handle the exceptions
              catch (Exception e) {
                  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; 
          } 
      } 
       static int computeXOR(int n)
      {
          // If n is a multiple of 4
          if (n % 4 == 0)
              return n;
        
          // If n%4 gives remainder 1
          if (n % 4 == 1)
              return 1;
        
          // If n%4 gives remainder 2
          if (n % 4 == 2)
              return n + 1;
        
          // If n%4 gives remainder 3
          return 0;
      }
      public static void main (String[] args) throws java.lang.Exception
      {
  
         try{
          FastReader sc=new FastReader();
          BufferedWriter out = new BufferedWriter(
              new OutputStreamWriter(System.out));
          int t=sc.nextInt();
          while(t-->0)
          {
              int n  = sc.nextInt();
              int arr[] = new int[n];
              for(int i=0;i<n;i++)
                  arr[i]=sc.nextInt();
              int count1=0;
              int count0=0;
              for(int i=0;i<n;i++)
                  if(arr[i]==1)
                      count1++;
                  else if(arr[i]==0)
                      count0++;
  
              long ans=0;
              while(count1-->0)
                  ans+=Math.pow(2,count0);
              System.out.println(ans);
          }
      }catch(Exception e){
              return;
          }
      }
  }