description: Petya has got an interesting flower. Petya is a busy person, so he sometimes forgets to water it. You are given n days from Petya's live and you have to determine what happened with his flower in the end.
  
  The flower grows as follows: 
  
    * If the flower isn't watered for two days in a row, it dies. 
    * If the flower is watered in the i-th day, it grows by 1 centimeter. 
    * If the flower is watered in the i-th and in the (i-1)-th day (i > 1), then it grows by 5 centimeters instead of 1. 
    * If the flower is not watered in the i-th day, it does not grow. 
  
  
  
  At the beginning of the 1-st day the flower is 1 centimeter tall. What is its height after n days?
  
  Input
  
  Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 100). Description of the test cases follows.
  
  The first line of each test case contains the only integer n (1 ≤ n ≤ 100).
  
  The second line of each test case contains n integers a_1, a_2, ..., a_n (a_i = 0 or a_i = 1). If a_i = 1, the flower is watered in the i-th day, otherwise it is not watered.
  
  Output
  
  For each test case print a single integer k — the flower's height after n days, or -1, if the flower dies.
  
  Example
  
  Input
  
  
  4
  3
  1 0 1
  3
  0 1 1
  4
  1 0 0 1
  1
  0
  
  
  Output
  
  
  3
  7
  -1
  1
solution: # template taken from https://github.com/cheran-senthil/PyRival/blob/master/templates/template.py
  
  import os
  import sys
  from io import BytesIO, IOBase
  import math
  from heapq import heappop, heappush, heapify
  from collections import deque
  
  def read():
      sys.stdin  = open('input.txt', 'r')  
      sys.stdout = open('output.txt', 'w') 
  
  # ------------------------------------------- Algos --------------------------------------------------------
  
  def lower_bound(arr, n, k):
      start = 0
      end = n-1
      while start <= end:
          mid = (start+end)//2
          if arr[mid] == k:
              return mid
          elif arr[mid] > k:
              if mid > 0:
                  if arr[mid-1] < k:
                      return (mid-1)
              else:
                  return -1
          else:
              if mid < (n-1):
                  if arr[mid+1] > k:
                      return mid
              else:
                  return mid
  def upper_bound(arr, n, k):
      start = 0
      end = n-1
      while start <= end:
          mid = (start+end)//2
          if arr[mid] == k:
              return mid
          elif arr[mid] > k:
              if mid > 0:
                  if arr[mid-1] < k:
                      return (mid)
              else:
                  return mid
          else:
              if mid < (n-1):
                  if arr[mid+1] > k:
                      return (mid+1)
              else:
                  return -1
  def gcd(a,b):
      if a == 0:
          return b
      return gcd(b % a, a)
  def lcm(a,b):
      return (a // gcd(a,b))* b
  
  # -------------------------------------------------- code -------------------------------------------------
  def helper():
      pass
  
  def main():
   
      t = int(input())
      for _ in range(t):
          n = int(input())
          arr = list(map(int, input().split()))
  
          ans = 1
          flag = True
          for i in range(n):
              if i >= 1:
                  if arr[i-1] == 0 and arr[i] == 0:
                      flag = False
                      break
  
                  elif arr[i-1] == 1 and arr[i] == 1:
                      ans += 5
  
                  elif arr[i-1] == 0 and arr[i] == 1:
                      ans += 1
  
  
              else:
                  if arr[i] == 1:
                      ans += 1
  
          if flag:
              print(ans)
  
          else:
              print(-1)
  
  
  # ---------------------------------------------- region fastio ---------------------------------------------
  BUFSIZE = 8192
  
  
  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")
  
  
  sys.stdin, sys.stdout = IOWrapper(sys.stdin), IOWrapper(sys.stdout)
  input = lambda: sys.stdin.readline().rstrip("\r\n")
  
  # -------------------------------------------------- end region ---------------------------------------------
  
  if __name__ == "__main__":
      #read()
      main()