rps

$($Exercise $5\mathrm{.}26$ from the textbook$)$ Write a function rps that returns the result of a game of "Rock,

Paper, Scissors". The function accepts two arguments, each one of $\text{'}R\text{'},\text{'}$P$\text{'},\text{'}$S$\text{'},$ that represents

the symbol played by each of the two players. The function returns:

$-1$ if the first player wins

$0$ if a tie

$1$ if the second player wins

Scissors beats Paper beats Rock beats Scissors

Sample usage: