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