Problem:
Score : 100 points

Problem Statement

We have weather records at AtCoder Town for some consecutive three days. A string of length 3, S, represents the records - if the i-th character is S, it means it was sunny on the i-th day; if that character is R, it means it was rainy on that day.

Find the maximum number of consecutive rainy days in this period.

Constraints

|S| = 3

Each character of S is S or R.

Input

Input is given from Standard Input in the following format:

S

Output

Print the maximum number of consecutive rainy days in the period.

Sample Input 1

RRS

Sample Output 1

2

We had rain on the 1-st and 2-nd days in the period. Here, the maximum number of consecutive rainy days is 2, so we should print 2.

Sample Input 2

SSS

Sample Output 2

0

It was sunny throughout the period. We had no rainy days, so we should print 0.

Sample Input 3

RSR

Sample Output 3

1

We had rain on the 1-st and 3-rd days - two "streaks" of one rainy day, so we should print 1.

Solution in Haskell (GHC 8.8.3) (judge verdict: Accepted)

module Main where

consecLength :: Eq a => a -> [a] -> Integer
consecLength a xs = maximum $ f 0 a xs
	where   f :: Eq a => Integer -> a -> [a] -> [Integer]
		f _ _ [] = []
		f n a (x:xs)
			| a == x = n + 1 : (f (n + 1) a xs)
			| otherwise = 0 : (f 0 a xs)

main :: IO ()
main = getLine >>= putStrLn . show . consecLength 'R'