import java.util.*;
import java.lang.*;
public class Main
{
  public static void main(String args[])
  {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    if(s.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R')
      System.out.println(3);
    else if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      System.out.println(1);
    else
        System.out.println(0);
	}
} import java.util.*; util.* java import java.lang.*; lang.* java public class Main
{
  public static void main(String args[])
  {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    if(s.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R')
      System.out.println(3);
    else if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      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.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R')
      System.out.println(3);
    else if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      System.out.println(1);
    else
        System.out.println(0);
	} main {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    if(s.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R')
      System.out.println(3);
    else if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      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.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R')
      System.out.println(3);
    else if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      System.out.println(1);
    else
        System.out.println(0); s.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R' s.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R' s.charAt(0)=='R' s.charAt(0) s.charAt s 0 'R' s.charAt(1)=='R' s.charAt(1) s.charAt s 1 'R' s.charAt(2)=='R' s.charAt(2) s.charAt s 2 'R' System.out.println(3) System.out.println System.out System System.out 3 if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      System.out.println(1);
    else
        System.out.println(0); s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R') s.charAt(1)=='R' s.charAt(1) s.charAt s 1 'R' (s.charAt(0)=='R' || s.charAt(2)=='R') s.charAt(0)=='R' s.charAt(0) s.charAt s 0 'R' s.charAt(2)=='R' s.charAt(2) s.charAt s 2 'R' System.out.println(2) System.out.println System.out System System.out 2 if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      System.out.println(1);
    else
        System.out.println(0); s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R' s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R' s.charAt(0)=='R' s.charAt(0) s.charAt s 0 'R' s.charAt(1)=='R' s.charAt(1) s.charAt s 1 'R' s.charAt(2)=='R' s.charAt(2) s.charAt s 2 'R' System.out.println(1) System.out.println System.out System System.out 1 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 sc = new Scanner(System.in);
    String s = sc.next();
    if(s.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R')
      System.out.println(3);
    else if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      System.out.println(1);
    else
        System.out.println(0);
	}
} public class Main
{
  public static void main(String args[])
  {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    if(s.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R')
      System.out.println(3);
    else if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      System.out.println(1);
    else
        System.out.println(0);
	}
} Main
import java.util.*;
import java.lang.*;
public class Main
{
  public static void main(String args[])
  {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    if(s.charAt(0)=='R' && s.charAt(1)=='R' && s.charAt(2)=='R')
      System.out.println(3);
    else if(s.charAt(1)=='R' && (s.charAt(0)=='R' || s.charAt(2)=='R'))
      System.out.println(2);
    else if(s.charAt(0)=='R' || s.charAt(1)=='R' || s.charAt(2)=='R')
      System.out.println(1);
    else
        System.out.println(0);
	}
}