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 math
  import os
  import sys
  from io import BytesIO, IOBase
  M = 1000000007
  import random
  import heapq
  import threading
  import bisect
  import time
  from functools import *
  from collections import *
  from itertools import *
  BUFSIZE = 8192
  import array
  class FastIO(IOBase):
      newlines = 0
      def __init__(self, file):
          self._fd = file.fileno()
          self.buffer = BytesIO()
          self.writable = "x" in file.mode or "r" not in file.mode
          self.write = self.buffer.write if self.writable else None
      def read(self):
          while True:
              b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
              if not b:
                  break
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
          self.newlines = 0
          return self.buffer.read()
      def readline(self):
          while self.newlines == 0:
              b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
              self.newlines = b.count(b"\n") + (not b)
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
          self.newlines -= 1
          return self.buffer.readline()
      def flush(self):
          if self.writable:
              os.write(self._fd, self.buffer.getvalue())
              self.buffer.truncate(0), self.buffer.seek(0)
  class IOWrapper(IOBase):
      def __init__(self, file):
          self.buffer = FastIO(file)
          self.flush = self.buffer.flush
          self.writable = self.buffer.writable
          self.write = lambda s: self.buffer.write(s.encode("ascii"))
          self.read = lambda: self.buffer.read().decode("ascii")
          self.readline = lambda: self.buffer.readline().decode("ascii")
  def print(*args, **kwargs):
      sep, file = kwargs.pop("sep", " "), kwargs.pop("file", sys.stdout)
      at_start = True
      for x in args:
          if not at_start:
              file.write(sep)
          file.write(str(x))
          at_start = False
      file.write(kwargs.pop("end", "\n"))
      if kwargs.pop("flush", False):
          file.flush()
  if sys.version_info[0] < 3:
      sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
  else:
      sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
  input = lambda: sys.stdin.readline().rstrip("\r\n")
  def inp(): return sys.stdin.readline().rstrip("\r\n")  # for fast input
  def out(var): sys.stdout.write(str(var))  # for fast output, always take string
  def lis(): return list(map(int, inp().split()))
  def stringlis(): return list(map(str, inp().split()))
  def sep(): return map(int, inp().split())
  def strsep(): return map(str, inp().split())
  def fsep(): return map(float, inp().split())
  def inpu(): return int(inp())
  
  def build(arr,a,b,st,node):
      if a==b:
          st[node] =  arr[a]
          return st[node]
      mid = (a+b)//2
      st[node] = min(build(arr,a,mid,st,2*node+1) , build(arr,mid+1,b,st,2*node+2))
      return st[node]
  
  def getmin(arr,a,b,l,r,st,node):
      if l>b or r<a:
          return float("inf")
      if l<=a and r>=b:
          return st[node]
      mid = (a+b)//2
      return min(getmin(arr,a,mid,l,r,st,2*node+1),getmin(arr,mid+1,b,l,r,st,2*node+2))
  
  def chck(x,y,z):
      #print(x[0]*(y[1]-z[1]) + y[0]*(z[1]-x[1]) + z[0]*(x[1]-y[1]))
      if abs(x[0]*(y[1]-z[1]) + y[0]*(z[1]-x[1]) + z[0]*(x[1]-y[1]))>0:
          return True
      return False
  
  def main():
      t = 1
      t=int(input())
      for _ in range(t):
          n = inpu()
          arr = lis()
          #s = sum(arr) - 1
          if arr.count(1)==0:
              print(0)
              continue
          one = arr.count(1)
          zero = arr.count(0)
          #one-=1
          c = zero
          print(2**(c)*one)
  if __name__ == '__main__':
      """
      threading.stack_size(2*10**8)
      threading.Thread(target=main).start()
      """
      main()
  