import java.util.*;

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

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