import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    String S =sc.next();
    if(S.contains("RRR")){System.out.println(3);}
    else if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("R")){System.out.println(1);}
    else{System.out.println(0);}
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    String S =sc.next();
    if(S.contains("RRR")){System.out.println(3);}
    else if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("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.contains("RRR")){System.out.println(3);}
    else if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("R")){System.out.println(1);}
    else{System.out.println(0);}
  } main {
    Scanner sc =new Scanner(System.in);
    String S =sc.next();
    if(S.contains("RRR")){System.out.println(3);}
    else if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("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.contains("RRR")){System.out.println(3);}
    else if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("R")){System.out.println(1);}
    else{System.out.println(0);} S.contains("RRR") S.contains S "RRR" {System.out.println(3);} System.out.println(3) System.out.println System.out System System.out 3 if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("R")){System.out.println(1);}
    else{System.out.println(0);} S.contains("RR") S.contains S "RR" {System.out.println(2);} System.out.println(2) System.out.println System.out System System.out 2 if(S.contains("R")){System.out.println(1);}
    else{System.out.println(0);} S.contains("R") S.contains S "R" {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 sc =new Scanner(System.in);
    String S =sc.next();
    if(S.contains("RRR")){System.out.println(3);}
    else if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("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.contains("RRR")){System.out.println(3);}
    else if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("R")){System.out.println(1);}
    else{System.out.println(0);}
  }
} Main
import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    String S =sc.next();
    if(S.contains("RRR")){System.out.println(3);}
    else if(S.contains("RR")){System.out.println(2);}
    else if(S.contains("R")){System.out.println(1);}
    else{System.out.println(0);}
  }
}