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.io.PrintWriter;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.StringTokenizer;
  
  public class _1582_B {
  
      private static final FastScanner in = new FastScanner();
      private static final PrintWriter out = new PrintWriter(System.out);
      private static final PrintWriter err = new PrintWriter(System.err);
  
      public static void solve() {
          int n = in.nextInt();
          int[] arr = in.nextIntArray(n);
  
          long count1 = 0;
          long count0 = 0;
  
          for (int a : arr) {
              if (a == 0) count0++;
              if (a == 1) count1++;
          }
  
          out.println(count1 * (1L << count0));
      }
  
      // Boilerplate
      public static void main(String[] args) {
          int t = in.nextInt();
          while (t-- > 0) {
              solve();
          }
  
          err.close();
          out.close();
      }
  
      @SuppressWarnings("unused")
      static class FastScanner {
  
          StringTokenizer tok = new StringTokenizer("");
          BufferedReader in;
  
          FastScanner() {
              in = new BufferedReader(new InputStreamReader(System.in));
          }
  
          String next() {
              while (!tok.hasMoreElements()) {
                  try {
                      tok = new StringTokenizer(in.readLine());
                  } catch (IOException e) {
                      throw new RuntimeException(e);
                  }
              }
  
              return tok.nextToken();
          }
  
          String nextLine() {
              String line;
              try {
                  line = in.readLine();
              } catch (IOException e) {
                  throw new RuntimeException(e);
              }
              return line;
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          int[] nextIntArray(int n) {
              int[] arr = new int[n];
              for (int i = 0; i < n; i++) {
                  arr[i] = nextInt();
              }
              return arr;
          }
  
          List<Integer> nextIntegerList(int n) {
              ArrayList<Integer> list = new ArrayList<>(n);
              for (int i = 0; i < n; i++) {
                  list.add(nextInt());
              }
              return list;
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
          long[] nextLongArray(int n) {
              long[] arr = new long[n];
              for (int i = 0; i < n; i++) {
                  arr[i] = nextLong();
              }
              return arr;
          }
  
          List<Long> nextLongList(int n) {
              ArrayList<Long> list = new ArrayList<>(n);
              for (int i = 0; i < n; i++) {
                  list.add(nextLong());
              }
              return list;
          }
  
          ArrayList<Integer>[] nextGraph(int n, int m) {
              @SuppressWarnings("unchecked")
              ArrayList<Integer>[] adj = (ArrayList<Integer>[]) new ArrayList[n];
  
              for (int i = 0; i < n; i++) {
                  adj[i] = new ArrayList<>();
              }
  
              for (int i = 0; i < m; i++) {
                  int v = nextInt();
                  int t = nextInt();
                  adj[v - 1].add(t - 1);
                  adj[t - 1].add(v - 1);
              }
  
              return adj;
          }
      }
  }