RockPaperScissors

Write a program that reads 2 characters from either the keyboard or a
file. The characters are either PP, PR, PS, RP,
RR, RS, SP, SR, or SS. They correspond to the selections made by 2
players playing the game of rock-paper-scissors.
Make the program accept inputs until one player’s score is more than 3
points ahead of the other.
Hint: remember that you can use .substring() to get the elements of a
String.