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 codeforces;
  
  import java.io.*;
  import java.util.*;
  
  public class Contest750_div2 {
  	static int nextInt() throws IOException {
  		return Integer.parseInt(next());
  	}
  
  	static long nextLong() throws IOException {
  		return Long.parseLong(next());
  	}
  
  	private static String next() throws IOException {
  
  		while (st == null || !st.hasMoreTokens()) {
  			st = new StringTokenizer(br.readLine());
  		}
  		return st.nextToken();
  	}
  
  	static BufferedReader br;
  	static StringTokenizer st;
  	static BufferedWriter bw;
  	static int m = (int) 1e9 + 7;
  	public static void main(String[] args) throws IOException {
  		br = new BufferedReader(new InputStreamReader(System.in));
  		bw = new BufferedWriter(new OutputStreamWriter(System.out));
  		int t = nextInt();
  		while (t-- > 0) {
  			lutnik_subsequences();
  		}
  		bw.close();
  	}
  	
  	public static void luntik_concerts() throws IOException{
  		long a=nextLong();
  		long b=nextLong();
  		long c=nextLong();
  		long s=a+b*2+c*3;
  		if(s%2==0) {
  			bw.append(0+"\n");
  		}else {
  			bw.append(1+"\n");
  		}
  	}
  	
  	public static void lutnik_subsequences() throws IOException{
  		int n=nextInt();
  		int[]arr=new int[n];
  		int a=0,b=0;
  		for(int i=0;i<n;i++) {
  			arr[i]=nextInt();
  			if(arr[i]==1) {
  				b++;
  			}
  			if(arr[i]==0) {
  				a++;
  			}
  		}
  		if(b==0) {
  			bw.append(0+"\n");
  			return;
  		}
  
  		long x=0;
  		x=(1L<<a);
  		x*=b;
  		
  		bw.append(x +"\n");
  		
  	}
  	
  	
  	
  	
  }
  