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