import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 文字列の入力
		String s = sc.next();
		// 出力
		if(s.indexOf("RRR") != -1){
		    System.out.println(3);
		}
		else if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    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);
		// 文字列の入力
		String s = sc.next();
		// 出力
		if(s.indexOf("RRR") != -1){
		    System.out.println(3);
		}
		else if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    System.out.println(1);
		}
		else{
		    System.out.println(0);
		}
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 文字列の入力
		String s = sc.next();
		// 出力
		if(s.indexOf("RRR") != -1){
		    System.out.println(3);
		}
		else if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    System.out.println(1);
		}
		else{
		    System.out.println(0);
		}
	} main {
		Scanner sc = new Scanner(System.in);
		// 文字列の入力
		String s = sc.next();
		// 出力
		if(s.indexOf("RRR") != -1){
		    System.out.println(3);
		}
		else if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    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.indexOf("RRR") != -1){
		    System.out.println(3);
		}
		else if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    System.out.println(1);
		}
		else{
		    System.out.println(0);
		} s.indexOf("RRR") != -1 s.indexOf("RRR") s.indexOf s "RRR" -1 1 {
		    System.out.println(3);
		} System.out.println(3) System.out.println System.out System System.out 3 if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    System.out.println(1);
		}
		else{
		    System.out.println(0);
		} s.indexOf("RR") != -1 s.indexOf("RR") s.indexOf s "RR" -1 1 {
		    System.out.println(2);
		} System.out.println(2) System.out.println System.out System System.out 2 if(s.indexOf("R") != -1){
		    System.out.println(1);
		}
		else{
		    System.out.println(0);
		} s.indexOf("R") != -1 s.indexOf("R") s.indexOf s "R" -1 1 {
		    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);
		// 文字列の入力
		String s = sc.next();
		// 出力
		if(s.indexOf("RRR") != -1){
		    System.out.println(3);
		}
		else if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    System.out.println(1);
		}
		else{
		    System.out.println(0);
		}
	}
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 文字列の入力
		String s = sc.next();
		// 出力
		if(s.indexOf("RRR") != -1){
		    System.out.println(3);
		}
		else if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    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);
		// 文字列の入力
		String s = sc.next();
		// 出力
		if(s.indexOf("RRR") != -1){
		    System.out.println(3);
		}
		else if(s.indexOf("RR") != -1){
		    System.out.println(2);
		}
		else if(s.indexOf("R") != -1){
		    System.out.println(1);
		}
		else{
		    System.out.println(0);
		}
	}
}