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: # Sujith
  from sys import stdin,stdout,setrecursionlimit
  from io import BytesIO, IOBase
  # from heapq import heappush as push,heappop as hp,heapify as h
  from math import gcd,floor,sqrt,ceil
  # from collections import Counter,deque as dq,defaultdict as dd
  # from itertools import accumulate as acc,permutations as perm
  # from bisect import bisect_left as bl,bisect_right as br,bisect as bis
  
  setrecursionlimit(10000)
  
  class FastIO(IOBase):
      newlines = 0
  
      def __init__(self, file):
          import os
          self.os = os
          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
          self.BUFSIZE = 8192
  
      def read(self):
          while True:
              a = self.os.read(self._fd, max(self.os.fstat(self._fd).st_size, self.BUFSIZE))
              if not a:
                  break
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(a), self.buffer.seek(ptr)
          self.newlines = 0
          return self.buffer.read()
  
      def readline(self):
          while self.newlines == 0:
              a = self.os.read(self._fd, max(self.os.fstat(self._fd).st_size, self.BUFSIZE))
              self.newlines = a.count(b"\n") + (not a)
              ptr = self.buffer.tell()
              self.buffer.seek(0, 2), self.buffer.write(a), self.buffer.seek(ptr)
          self.newlines -= 1
          return self.buffer.readline()
  
      def flush(self):
          if self.writable:
              self.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")
  
  
  stdin, stdout = IOWrapper(stdin), IOWrapper(stdout)
  input = lambda: stdin.readline().rstrip("\r\n")
  
  # inf = float('inf')
  # ninf = float('-inf')
  # abc = 'abcdefghijklmnopqrstuvwxyz'
  inp = lambda: int(input())
  st = lambda: input().strip()
  jn = lambda x,l: x.join(map(str,l))
  int_arr = lambda : list(map(int,input().strip().split()))
  str_arr = lambda :list(map(str,input().split()))
  get_str = lambda : map(str,input().strip().split())
  get_int = lambda: map(int,input().strip().split())
  get_float = lambda : map(float,input().strip().split())
  
  mod = 1000000007
  
  #main()
  for _ in range(inp()):
      n = inp()
      arr = int_arr()
  
      h = 1
      cond = True
      ct = 0
      for i in range(n):
          if i > 0 and arr[i] == 1 and arr[i - 1] == 1:
              h += 5
              ct = 0
          elif arr[i] == 1:
              h += 1
              ct = 0
          else:
              ct += 1
          if ct == 2:
              cond = False
              break
      if cond:
          print(h)
      else:
          print(-1)