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.lang.reflect.Array;
  import java.util.*;
  import java.io.*;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  public class Main {
  
      public static void main(String[] args) {
          // write your code here
          PrintWriter out = new PrintWriter(System.out);
          FastReader scan = new FastReader();
          Task solver = new Task();
          solver.solve(1,scan,out);
          out.close();
  
  
      }
  
      static class Task{
  
          public void solve(int testNumber, FastReader scan, PrintWriter out) {
              int [][] L = {{1,3,3,4,5,5,6},{2,2,4,1,1,4,2}};
  
  
  
  
  
              int t = scan.nextInt();
  
  
              for(int i=0; i<t;i++){
                  int n = scan.nextInt();
                  ArrayList<Integer> list = new ArrayList<>();
  
                  int oneCounter=0;
                  int zeroCOunter=0;
                  for(int j=0; j<n;j++){
                      int current = scan.nextInt();
                      if(current==1){
                          oneCounter++;
                      }
                      if(current==0){
                          zeroCOunter++;
                      }
  
                  }
                  long answer = (long)Math.pow(2,zeroCOunter)*oneCounter;
                  out.println(answer);
  
  
  
  
  
  
  
  
  
              }
  
  
          }
  
          public static String parenthesys(int n){
              String answer = "";
              for(int j = 0; j<n;j++){
                  answer+="(";
              }
              for(int j = 0; j<n;j++){
                  answer+=")";
              }
              return answer;
          }
          public static long digitsSum(long n){
              long sum=0;
              while(n!=0){
                  sum+=n%10;
                  n=n/10;
              }
              return sum;
          }
          public static boolean isValid(int x, int y, int n){
              if(x<0 || y<0 || x>=n || y>=n){
                  return false;
              }
              return true;
          }
  
          public static int factorial(int n){
              if(n<=1){
                  return 1;
              }else{
                  return n*factorial(n-1);
              }
          }
  
          public static long DBD(long a, long b){
              long answer=1;
              for(long i=1; i<=Math.min(a,b);i++){
                  if(a%i==0 && b%i==0){
                      answer=i;
                  }
              }
              return answer;
          }
          public static boolean isPrime(int n){
              if(n<2){
                  return false;
              }
              for(int i=2; i<Math.sqrt(n)+1 ;i++){
                  if(n%i==0){
                      return false;
                  }
              }
              return true;
          }
      }
      static class FastReader {
          BufferedReader br;
          StringTokenizer st;
  
          public FastReader() {
              br = new BufferedReader(new InputStreamReader(System.in));
          }
  
          public FastReader(String s) throws FileNotFoundException {
              br = new BufferedReader(new FileReader(new File(s)));
          }
  
          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;
          }
      }
  
  
  
  
  
  
  }
  
  