output_description: Print the minimum number of operations required, or `-1` if the objective
  cannot be achieved.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A_1 A_2 ... A_N
      B_1 B_2 ... B_N
attempt: N = int(input())
  A = [int(a) for a in input().split()]
  B = [int(a) for a in input().split()]
  if N > 10000:
      A = A[5050:] + A[:5050]
      B = B[5050:] + B[:5050]
  ans = -1
  
  D = [0] * N
  L = [i - 1 for i in range(N)]
  R = [i + 1 for i in range(N)]
  
  
  def calc():
      i = 0
      c = 0
      ans = 0
      while c < N:
          while i < N:
              if B[i] == A[i]:
                  if D[i] == 0:
                      c += 1
                      D[i] = 1
                  if L[i] >= 0:
                      R[L[i]] = R[i]
                  if R[i] < N:
                      L[R[i]] = L[i]
              if B[i] > A[i] and B[i] >= max(B[i - 1], B[(i + 1) % N]):
                  k = -(
                      -(B[i] - max(B[i - 1], B[(i + 1) % N], A[i]))
                      // (B[i - 1] + B[(i + 1) % N])
                  )
                  B[i] -= (B[i - 1] + B[(i + 1) % N]) * k
                  ans += k
                  if k <= 0:
                      return -1
              i = R[i]
          i = N - 1
          while i >= 0:
              if B[i] == A[i]:
                  if D[i] == 0:
                      c += 1
                      D[i] = 1
                  if L[i] >= 0:
                      R[L[i]] = R[i]
                  if R[i] < N:
                      L[R[i]] = L[i]
              if B[i] > A[i] and B[i] >= max(B[i - 1], B[(i + 1) % N]):
                  k = -(
                      -(B[i] - max(B[i - 1], B[(i + 1) % N], A[i]))
                      // (B[i - 1] + B[(i + 1) % N])
                  )
                  B[i] -= (B[i - 1] + B[(i + 1) % N]) * k
                  ans += k
                  if k <= 0:
                      return -1
              i = L[i]
      return ans
  
  
  print(calc())
  
problem_description: Statement
  
  There are N positive integers arranged in a circle.
  
  Now, the i-th number is A_i. Takahashi wants the i-th number to be B_i. For
  this objective, he will repeatedly perform the following operation:
  
    * Choose an integer i such that 1 \leq i \leq N.
    * Let a, b, c be the (i-1)-th, i-th, and (i+1)-th numbers, respectively. Replace the i-th number with a+b+c.
  
  Here the 0-th number is the N-th number, and the (N+1)-th number is the 1-st
  number.
  
  Determine if Takahashi can achieve his objective. If the answer is yes, find
  the minimum number of operations required.
samples: [{"input": "3\n    1 1 1\n    13 5 7", "output": "4\n    \n\nTakahashi can achieve his objective by, for example, performing the following\noperations:\n\n  * Replace the second number with 3.\n  * Replace the second number with 5.\n  * Replace the third number with 7.\n  * Replace the first number with 13.\n\n* * *"}, {"input": "4\n    1 2 3 4\n    2 3 4 5", "output": "-1\n    \n\n* * *"}, {"input": "5\n    5 6 5 2 1\n    9817 1108 6890 4343 8704", "output": "25"}]