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 eround101;
  
  import java.util.*;
  import java.io.*;
  import java.lang.*;
  import java.util.StringTokenizer;
  
  public class Solution {
  
      static HritikScanner sc = new HritikScanner();
      static PrintWriter pw = new PrintWriter(System.out, true);
      final static int MOD = 1000000007;
      static StringBuilder sb = new StringBuilder();
  
      public static void main(String[] args) {
  
          int t = ni();
          while (t-- > 0) {
              solve();
          }
      }
  
      static void solve() {
  //        int a = ni();
  //        int b = ni();
  //        int c = ni();
  //        a = a%2;
  //        b = b%2;
  //        c = c%2;
  //        int[] arr = new int[3];
  //        arr[0] = a*1;
  //        arr[1] = b*2;
  //        arr[2] = c*3;
  //        Arrays.sort(arr);
  //        pl(arr[2]-(arr[0]+arr[1]));
          int n = ni();
          long[] arr = nextLongArray(n);
          int c = 0;
          boolean flag = false;
          long c1 = 0;
          for(int i = 0; i < n; i++)
          {
              if(arr[i] == 1)
                  flag = true;
              if(arr[i] == 0)
                  c++;
              if(arr[i] == 1)
              {
                  c1++;
              }
          }
          if(!flag)
          {
              pl(0);
              return;
          }
          pl((c1*(long)Math.pow(2, c)));
  
      }
  
      /////////////////////////////////////////////////////////////////////////////////
      static class FenwickTree { // Binary Index Tree
  
          int[] tree;
          static int size;
  
          public FenwickTree(int size) {
              this.size = size;
              tree = new int[size + 5];
          }
  
          public void add(int i, int val) {
              while (i <= size) {
                  tree[i] += val;
                  i += i & -i;  // adding the decimal value of the last set bit.
              }
          }
  
          public int sum(int i) {
              int res = 0;
              while (i >= 1) {
                  res += tree[i];
                  i -= i & -i; // deleting the last set bit
              }
              return res;
          }
  
          public int sum(int l, int r) {
              return sum(r) - sum(l - 1);
          }
      }
  
      /////////////////////////////////////////////////////////////////////////////////
      static int[] nextIntArray(int n) {
          int[] arr = new int[n];
          int i = 0;
          while (i < n) {
              arr[i++] = ni();
          }
          return arr;
      }
  
      static long[] nextLongArray(int n) {
          long[] arr = new long[n];
          int i = 0;
          while (i < n) {
              arr[i++] = nl();
          }
          return arr;
      }
  
      static int[] nextIntArray1(int n) {
          int[] arr = new int[n + 1];
          int i = 1;
          while (i <= n) {
              arr[i++] = ni();
          }
          return arr;
      }
  
      /////////////////////////////////////////////////////////////////////////////////
      static int ni() {
          return sc.nextInt();
      }
  
      static long nl() {
          return sc.nextLong();
      }
  
      static double nd() {
          return sc.nextDouble();
      }
  
      /////////////////////////////////////////////////////////////////////////////////
      static void pl() {
          pw.println();
      }
  
      static void p(Object o) {
          pw.print(o + " ");
      }
  
      static void pl(Object o) {
          pw.println(o);
      }
  
      static void psb(StringBuilder sb) {
          pw.print(sb);
      }
  
      static void pa(Object arr[]) {
          for (Object o : arr) {
              p(o);
          }
          pl();
      }
  
      static void pa(int arr[]) {
          for (int o : arr) {
              p(o);
          }
          pl();
      }
  
      static void pa(long arr[]) {
          for (long o : arr) {
              p(o);
          }
          pl();
      }
  
      static void pa(double arr[]) {
          for (double o : arr) {
              p(o);
          }
          pl();
      }
  
      static void pa(char arr[]) {
          for (char o : arr) {
              p(o);
          }
          pl();
      }
  
      static void pa(List list) {
          for (Object o : list) {
              p(o);
          }
          pl();
      }
  
      static void pa(Object[][] arr) {
  
          for (int i = 0; i < arr.length; ++i) {
              for (Object o : arr[i]) {
                  p(o);
              }
              pl();
          }
      }
  
      static void pa(int[][] arr) {
          for (int i = 0; i < arr.length; ++i) {
              for (int o : arr[i]) {
                  p(o);
              }
              pl();
          }
      }
  
      static void pa(long[][] arr) {
          for (int i = 0; i < arr.length; ++i) {
              for (long o : arr[i]) {
                  p(o);
              }
              pl();
          }
      }
  
      static void pa(char[][] arr) {
          for (int i = 0; i < arr.length; ++i) {
              for (char o : arr[i]) {
                  p(o);
              }
              pl();
          }
      }
  
      static void pa(double[][] arr) {
          for (int i = 0; i < arr.length; ++i) {
              for (double o : arr[i]) {
                  p(o);
              }
              pl();
          }
      }
  
  /////////////////////////////////////////////////////////////////////////////////
      static void print(Object s) {
          System.out.println(s);
      }
  
      /////////////////////////////////////////////////////////////////////////////////
      //-----------HritikScanner class for faster input----------//
      static class HritikScanner {
  
          BufferedReader br;
          StringTokenizer st;
  
          public HritikScanner() {
              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 class Pair implements Comparable<Pair> {
  
          int num, row, col;
  
          Pair(int num, int row, int col) {
              this.num = num;
              this.row = row;
              this.col = col;
          }
  
          public int get1() {
              return num;
          }
  
          public int get2() {
              return row;
          }
  
          public int compareTo(Pair A) {
              return this.num - A.num;
          }
  
          public String toString() {
              return num + " " + row + " " + col;
          }
      }
  
      //////////////////////////////////////////////////////////////////
      // Function to return gcd of a and b time complexity O(log(a+b))
      static long gcd(long a, long b) {
          if (a == 0) {
              return b;
          }
          return gcd(b % a, a);
      }
  
      // method to return LCM of two numbers 
      static long lcm(int a, int b) {
          return (a / gcd(a, b)) * b;
      }
  
      //////////////////////////////////////////////////////////////////
      static boolean isPrime(long n) {
          // Corner cases 
          if (n <= 1) {
              return false;
          }
          if (n <= 3) {
              return true;
          }
  
          // This is checked so that we can skip  
          // middle five numbers in below loop 
          if (n % 2 == 0 || n % 3 == 0) {
              return false;
          }
  
          for (long i = 5; i * i <= n; i = i + 6) {
              if (n % i == 0 || n % (i + 2) == 0) {
                  return false;
              }
          }
  
          return true;
      }
      //////////////////////////////////////////////////////////////////
  
      static boolean isPowerOfTwo(long n) {
          if (n == 0) {
              return false;
          }
  
          return (long) (Math.ceil((Math.log(n) / Math.log(2))))
                  == (long) (Math.floor(((Math.log(n) / Math.log(2)))));
      }
  
      public static long getFact(int n) {
          long ans = 1;
          while (n > 0) {
              ans *= n;
              ans %= MOD;
              n--;
          }
          return ans;
      }
  
      public static long pow(long n, int pow) {
          if (pow == 0) {
              return 1;
          }
          long temp = pow(n, pow / 2) % MOD;
          temp *= temp;
          temp %= MOD;
          if (pow % 2 == 1) {
              temp *= n;
          }
          temp %= MOD;
          return temp;
  
      }
  
      public static long nCr(int n, int r) {
          long ans = 1;
          int temp = n - r;
          while (n > temp) {
              ans *= n;
              ans %= MOD;
              n--;
          }
          ans *= pow(getFact(r) % MOD, MOD - 2) % MOD;
          ans %= MOD;
          return ans;
      }
  
      //////////////////////////////////////////////////////////////////
      // method returns Nth power of A 
      static double nthRoot(int A, int N) {
  
          // intially guessing a random number between 
          // 0 and 9 
          double xPre = Math.random() % 10;
  
          // smaller eps, denotes more accuracy 
          double eps = 0.001;
  
          // initializing difference between two 
          // roots by INT_MAX 
          double delX = 2147483647;
  
          // xK denotes current value of x 
          double xK = 0.0;
  
          // loop untill we reach desired accuracy 
          while (delX > eps) {
              // calculating current value from previous 
              // value by newton's method 
              xK = ((N - 1.0) * xPre
                      + (double) A / Math.pow(xPre, N - 1)) / (double) N;
              delX = Math.abs(xK - xPre);
              xPre = xK;
          }
  
          return xK;
      }
  
  }
  