import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        if (s.equals("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.equals("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.equals("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.equals("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.equals("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.equals("RRR") s.equals s "RRR" 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 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 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.equals("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.equals("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.equals("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");
    }
}