output_description: If A + B is 10 or greater, print the string `error` (case-sensitive);
  otherwise, print the value of A + B.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B
attempt: N, A, B = list(map(int, input().split()))
  H = [int(input()) for _ in range(N)]
  
  from math import ceil
  
  
  def can_korosu(t):
      count = 0
      for h in H:
          count += ceil(max(0, h - t * B) / (A - B))
          if count > t:
              return False
      return True
  
  
  lo = 0
  hi = 10**9
  
  p = (lo, hi)
  for _ in range(50):
      mid = (hi + lo) // 2
      if can_korosu(mid):
          hi = mid
      else:
          lo = mid
      if p == (lo, hi):
          break
      p = (lo, hi)
  print(hi)
  
problem_description: Statement
  
  You are given two integers A and B as the input. Output the value of A + B.
  
  However, if A + B is 10 or greater, output `error` instead.
samples: [{"input": "6 3", "output": "9\n    \n\n* * *"}, {"input": "6 4", "output": "error"}]