import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        int ans = 0;

        switch(s){
            case "SSR":
            case "SRS":
            case "RSS":
            case "RSR":
                ans = 1;
                break;
            case "SRR":
            case "RRS":
                ans = 2;
                break;
            case "RRR":
                ans = 3;
                break;
        }

        System.out.print(ans);

    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz