import java.util.*;
public class Main {
	public static void main (String[] args) {
      Scanner sc = new Scanner(System.in);
      String S = sc.nextLine();
      if(S.equals("RRS") || S.equals("SRR"))
        System.out.println(2);
      else if(S.equals("RRR"))
        System.out.println(3);
      else if(S.equals("SSS"))
        System.out.println(0);
      else
          System.out.println(1);
              
    }
}
/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