次の書式のいずれか（同じプログラム内のすべてを処理する必要があります）に書かれた日付を指定すると、有効な
yyyy/mm/dd日付に解析されます。

17th May 2012
March 14th, 2016
20 February 2014
September 14, 2017
Sunday, June 8, 2015

ルール

• Dates will sometimes be invalid, ie. incorrect day for the
  month or number of months in a year, you must handle both cases.
  Either by erroring out or returning a consistent falsey value, you
  choose. (They will however stick to the template formats
  above)
• Padding for days and months less than 10 must be used to create
  a two digit output.
• Month names will always be the full name, not shortened to
  their three character counterparts.
• You can assume the year will always be within the 0000-9999
  range.
• Negative numbers need not be handled.
• You can create a full program or function so output can be in
  any format, printed to console or returned from a function.
• Input will always be a string, output must always be a string,
  if it makes it shorter to take it as a single argument in an array
  eg. ["17th May 2012"] you may do so and output can be
  the same ["2012/05/17"]
• You can assume spelling in input will be correct.

BONUS: cos who here doesnt like a challenge
😉

2016年3月14日または
2016年14月の入力形式を許可することができる場合は、 20バイト
>最後のバイト数が1未満の場合は1になります。

スペルの混乱を避けるために、それぞれの日の完全な数字がここにあります。

First, Second, Third, Fourth, Fifth, Sixth, Seventh, Eighth, Nineth, Tenth, Eleventh, Twelfth, Thirteenth, Fourteenth, Fifteenth, Sixteenth, Seventeenth, Eighteenth, Nineteenth, Twentieth, Twenty First, Twenty Second, Twenty Third, Twenty Fourth, Twenty Fifth, Twenty Sixth, Twenty Seventh, Twenty Eighth, Twenty Nineth, Thirtieth, Thirty First

テストケース

INPUT                           | Output
17th May 2012                   | 2012/05/17
March 14th, 2016                | 2016/03/14
20 February 2014                | 2014/02/20
September 14, 2017              | 2017/09/14
Sunday, June 8, 2015            | 2015/06/08
1st January 1918                | 1918/01/01

The Fourteenth of March, 2016   | 2016/03/14
March the Fourteenth, 2016      | 2016/03/14
November the Seventeenth, 2019  | 2019/11/17
The Thirtieth of April, 2016    | 2016/04/30

30 February 2014                | Invalid
September 99, 2017              | Invalid
Sunday, June8, 2015             | Invalid

The Thirty First of April, 2016 | Invalid