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.Scanner;
  import java.util.StringTokenizer;
  import java.io.*;
  public class Sollution {
  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());
  	}
  
  	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)throws Exception {
  		// TODO Auto-generated method stub
         FastReader sc = new FastReader();
         BufferedWriter ou = new BufferedWriter(
                 new OutputStreamWriter(System.out));
         int t = sc.nextInt();
         for(int o = 0;o<t;o++) {
      	   int n = sc.nextInt();
      	   long a =0;
      	   long one = 0;
      	   long zero = 0;
      	   for(int i = 0; i<n;i++) {
              a= sc.nextLong();
               if( a==0) {
              	 zero++;
               }else if(a==1) {
              	 one++;
               }
             }if(one==0) {
          	   ou.write(0 + "\n");
             }else if(one!=0 && zero==0) {
          	   ou.write(one + "\n");
             } else if(one!=0 && zero!=0) {
          	   ou.write(one*((long)Math.pow(2.0,new Double(zero))) +"\n");
             }
  	}ou.flush();
  }
  }
  