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 C++ (GCC 9.2.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < n; ++i)
using namespace std;
using ll = long long;

int main(){
    string s;
    cin >> s;
    size_t n; 
    n = s.size();
    bool flag = true;
    int ans = 0;
    int cnt = 0;
    rep(i,n){
        if(s[i]=='R'){
            if(flag==true) cnt++;
            else flag = true;
        }
        if(s[i]=='S'){
            flag = false;
            ans = max(ans,cnt);
            cnt = 0;
        }
    }
    ans = max(ans,cnt);
    cout << ans << endl;
    return 0;
}