output_description: Print the number of days before the next Sunday.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: a, b, x = [int(i) for i in input().split()]
  for i in range(1, 10):
      n = (x - b * i) / float(a)
      if n < 0:
          if i == 9:
              print(0)
          continue
      if len(str(int(n))) == i:
          print(int(n) + 1)
          break
      elif i == 9:
          print(10**9)
  
problem_description: Statement
  
  Given is a string S representing the day of the week today.
  
  S is `SUN`, `MON`, `TUE`, `WED`, `THU`, `FRI`, or `SAT`, for Sunday, Monday,
  Tuesday, Wednesday, Thursday, Friday, and Saturday, respectively.
  
  After how many days is the next Sunday (tomorrow or later)?
samples: [{"input": "SAT", "output": "1\n    \n\nIt is Saturday today, and tomorrow will be Sunday.\n\n* * *"}, {"input": "SUN", "output": "7\n    \n\nIt is Sunday today, and seven days later, it will be Sunday again."}]