input: Write a python function to determine the number of days in a given month.
  assert num_of_days("January") == "31 days"
  assert num_of_days("February") == "28 or 29 days"
  assert num_of_days("April") == "30 days"
  assert num_of_days("InvalidMonth") == "Invalid input"
output: def num_of_days(month):
      days_in_month = {
          "January": "31 days",
          "February": "28 or 29 days",
          "March": "31 days",
          "April": "30 days",
          "May": "31 days",
          "June": "30 days",
          "July": "31 days",
          "August": "31 days",
          "September": "30 days",
          "October": "31 days",
          "November": "30 days",
          "December": "31 days"
      }
      return days_in_month.get(month, "Invalid input")