output_description: Output what day of the week it is in a line. Use the following conventions in
  your output: "mon" for Monday, "tue" for Tuesday, "wed" for Wednesday, "thu"
  for Thursday, "fri" for Friday, "sat" for Saturday, and "sun" for Sunday.
input_description: The input is given in the following format.
  
      
      
      X
      
  
  The input line specifies a day X (1 ≤ X ≤ 30) in September 2017.
attempt: X = int(input())
  X = (X - 9) % 7
  if X < 0:
      X = X + 7
  y = ""
  if X == 0:
      y = "sat"
  elif X == 1:
      y = "sun"
  elif X == 2:
      y = "mon"
  elif X == 3:
      y = "tue"
  elif X == 4:
      y = "wed"
  elif X == 5:
      y = "thu"
  elif X == 6:
      y = "fri"
  print(y)
  
problem_description: Day of Week
  
  The 9th day of September 2017 is Saturday. Then, what day of the week is the
  X-th of September 2017?
  
  Given a day in September 2017, write a program to report what day of the week
  it is.
samples: [{"input": "1", "output": "fri"}, {"input": "9", "output": "sat"}, {"input": "30", "output": "sat"}]