import java.util.Scanner;
public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    String s = scan.next();
    if (s.equals("RRR")){
      System.out.println(3);
    }else if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    }
  }
} import java.util.Scanner; Scanner java.util public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    String s = scan.next();
    if (s.equals("RRR")){
      System.out.println(3);
    }else if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    }
  }
} Main public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    String s = scan.next();
    if (s.equals("RRR")){
      System.out.println(3);
    }else if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    }
  } main {
    Scanner scan = new Scanner(System.in);
    String s = scan.next();
    if (s.equals("RRR")){
      System.out.println(3);
    }else if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    }
  } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String s = scan.next(); s scan.next() scan.next scan if (s.equals("RRR")){
      System.out.println(3);
    }else if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    } s.equals("RRR") s.equals s "RRR" {
      System.out.println(3);
    } System.out.println(3) System.out.println System.out System System.out 3 if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    } s.equals("RRS") s.equals s "RRS" {
      System.out.println(2);
    } System.out.println(2) System.out.println System.out System System.out 2 if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    } s.equals("SRR") s.equals s "SRR" {
      System.out.println(2);
    } System.out.println(2) System.out.println System.out System System.out 2 if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    } s.equals("RSR") s.equals s "RSR" {
      System.out.println(1);
    } System.out.println(1) System.out.println System.out System System.out 1 if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    } s.equals("RSS") s.equals s "RSS" {
      System.out.println(1);
    } System.out.println(1) System.out.println System.out System System.out 1 if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    } s.equals("SRS") s.equals s "SRS" {
      System.out.println(1);
    } System.out.println(1) System.out.println System.out System System.out 1 if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    } s.equals("SSR") s.equals s "SSR" {
      System.out.println(1);
    } System.out.println(1) System.out.println System.out System System.out 1 {
      System.out.println(0);
    } System.out.println(0) System.out.println System.out System System.out 0 String[] args args public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    String s = scan.next();
    if (s.equals("RRR")){
      System.out.println(3);
    }else if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    }
  }
} public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    String s = scan.next();
    if (s.equals("RRR")){
      System.out.println(3);
    }else if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    }
  }
} Main
import java.util.Scanner;
public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    String s = scan.next();
    if (s.equals("RRR")){
      System.out.println(3);
    }else if (s.equals("RRS")){
      System.out.println(2);
    }else if (s.equals("SRR")){
      System.out.println(2);
    }else if (s.equals("RSR")){
      System.out.println(1);
    }else if (s.equals("RSS")){
      System.out.println(1);
    }else if (s.equals("SRS")){
      System.out.println(1);
    }else if (s.equals("SSR")){
      System.out.println(1);
    }else{
      System.out.println(0);
    }
  }
}
