import java.util.*;
public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        String S = sc.next();



        int c = 0;
        switch (S){
            case("RRR"): c=3; break;
            case("SSS"): c=0; break;
            case("RRS"): c=2; break;
            case("SRR"): c=2; break;
            default: c=1; break;
        }



        System.out.println(c);

    }
}
/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