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