import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String input = sc.next();
    sc.close();
    if("SSS".equals(input)){
      System.out.println(0);
    } else if("RRS".equals(input) || "SRR".equals(input)){
      System.out.println(2);
    } else if("RRR".equals(input)){
      System.out.println(3);
    } 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