output_description: Print the answer.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A_1 A_2 ... A_N
attempt: # try:
  
  n = int(input())
  a = list(map(int, input().split()))
  
  i = 0
  count = 0
  while (i < n - 1):
      if a[i] <= a[i+1]:
          i += 1
      elif i == 0:
          a[i] = a[i] * -2
          count += 1
      else:
           if a[i+1] * -2 > 10 **9:
              count = -1
              break
          else:
              a[i+1] = a[i+1] * -2
              count += 1
  
  print(count)
  # except EOFError:
  #     pass
  
problem_description: Statement
  
  There are N positive integers A_1, A_2, ..., A_N. Takahashi can perform the
  following operation on these integers any number of times:
  
    * Choose 1 \leq i \leq N and multiply the value of A_i by -2.
  
  Notice that he multiplies it by **minus** two.
  
  He would like to make A_1 \leq A_2 \leq ... \leq A_N holds. Find the minimum
  number of operations required. If it is impossible, print `-1`.
samples: [{"input": "4\n    3 1 4 1", "output": "3\n    \n\nOne possible solution is:\n\n  * Choose i=4 and multiply the value of A_4 by -2. A_1, A_2, A_3, A_4 are now 3, 1, 4, -2.\n  * Choose i=1 and multiply the value of A_1 by -2. A_1, A_2, A_3, A_4 are now -6, 1, 4, -2.\n  * Choose i=4 and multiply the value of A_4 by -2. A_1, A_2, A_3, A_4 are now -6, 1, 4, 4.\n\n* * *"}, {"input": "5\n    1 2 3 4 5", "output": "0\n    \n\nA_1 \\leq A_2 \\leq ... \\leq A_N holds before any operation is performed.\n\n* * *"}, {"input": "8\n    657312726 129662684 181537270 324043958 468214806 916875077 825989291 319670097", "output": "7"}]