import java.util.Scanner;

class Main{
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        sc.close();

        if(str.equals("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.Scanner; Scanner java.util class Main{
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        sc.close();

        if(str.equals("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();
        sc.close();

        if(str.equals("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();
        sc.close();

        if(str.equals("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 sc.close() sc.close sc if(str.equals("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.equals("RRR") str.equals str "RRR" {
            System.out.println("3");
        } System.out.println("3") System.out.println System.out System System.out "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" 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" {
            System.out.println("0");
        } System.out.println("0") System.out.println System.out System System.out "0" String args[] args
import java.util.Scanner;

class Main{
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        sc.close();

        if(str.equals("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");
        }
    }
}