input: Write a function to print the calendar of a specific month and year.
  assert print_calendar(2021, 5) == "      May 2021\nMo Tu We Th Fr Sa Su\n                1  2\n 3  4  5  6  7  8  9\n10 11 12 13 14 15 16\n17 18 19 20 21 22 23\n24 25 26 27 28 29 30\n31\n"
  assert print_calendar(2023, 10) == "    October 2023\nMo Tu We Th Fr Sa Su\n                   1\n 2  3  4  5  6  7  8\n 9 10 11 12 13 14 15\n16 17 18 19 20 21 22\n23 24 25 26 27 28 29\n30 31\n"
output: import calendar
  
  def print_calendar(year, month):
      cal = calendar.TextCalendar(calendar.MONDAY)
      cal_str = cal.formatmonth(year, month)
      return cal_str