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 Rust (1.42.0) (judge verdict: Accepted)

use std::io::*;
use std::str::*;

fn read<T: FromStr>(s: &mut StdinLock) -> Option<T> {
    let s = s.by_ref().bytes().map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>();
    s.parse::<T>().ok()
}

fn main(){
    let s = stdin();
    let mut s = s.lock();
    let s = &mut s;

    let xxx = read::<String>(s).unwrap();
	let mut n = 0;	
	if xxx == "SSS" { n = 0 }
	if xxx == "SSR" { n = 1 }
	if xxx == "SRS" { n = 1 }
	if xxx == "SRR" { n = 2 }
	if xxx == "RSS" { n = 1 }
	if xxx == "RSR" { n = 1 }
	if xxx == "RRS" { n = 2 }
	if xxx == "RRR" { n = 3 }
	println!("{}", n);
}