Write program that takes a date as input and outputs the date's season. The input is a string to represent the month and an int to represent the day.

Ex: If the input is:

April 11 

the output is:

Spring 

In addition, check if the string and int are valid (an actual month and day).

Ex: If the input is:

Blue 65 

the output is:

Invalid 

The dates for each season are:

Spring: March 20 - June 20

Summer: June 21 - September 21

Autumn: September 22 - December 20

Winter: December 21 - March 19