const MONTHS = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];

function nth(d) {
    if (d > 3 && d < 21) return 'th';
    switch (d % 10) {
      case 1:  return "st";
      case 2:  return "nd";
      case 3:  return "rd";
      default: return "th";
    }
  }

var talkingCalendar = function(date) {
  let datePieces = date.split("/");
  let year = Number(datePieces[0]);
  //Subtract one to go from 01 -> 00 for correct month mapping.
  let monthIndex = Number(datePieces[1]) - 1;
  let day = Number(datePieces[2]);

  const dateStr =  MONTHS[monthIndex] + " " + day + nth(day) + ", " + year;
  return dateStr;
};

var runTask3 = function() {
    console.log(talkingCalendar("2017/12/02"));
    console.log(talkingCalendar("2007/11/11"));
    console.log(talkingCalendar("1987/08/24"));
    /*
    December 2nd, 2017
    November 11th, 2007
    August 24th, 1987
    */
  };

  runTask3();