import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int cnt = 0;
		for(int i=0; i < 3; i++) {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		}
		System.out.println(cnt);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int cnt = 0;
		for(int i=0; i < 3; i++) {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		}
		System.out.println(cnt);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int cnt = 0;
		for(int i=0; i < 3; i++) {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		}
		System.out.println(cnt);
	} main {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int cnt = 0;
		for(int i=0; i < 3; i++) {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		}
		System.out.println(cnt);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc int cnt = 0; cnt 0 for(int i=0; i < 3; i++) {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		} int i=0; int i=0; i 0 i < 3 i 3 i++ i++ i {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		} {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		} if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			} S.charAt(i)=='R' S.charAt(i) S.charAt S i 'R' {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			} if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                } i==2&&S.charAt(1)=='S' i==2 i 2 S.charAt(1)=='S' S.charAt(1) S.charAt S 1 'S' {
                  cnt=0;
                } cnt=0 cnt 0 cnt++ cnt System.out.println(cnt) System.out.println System.out System System.out cnt String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int cnt = 0;
		for(int i=0; i < 3; i++) {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		}
		System.out.println(cnt);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int cnt = 0;
		for(int i=0; i < 3; i++) {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		}
		System.out.println(cnt);
	}
} Main
import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int cnt = 0;
		for(int i=0; i < 3; i++) {
			if(S.charAt(i)=='R') {
				if(i==2&&S.charAt(1)=='S'){
                  cnt=0;
                }
				  cnt++;
			}
		}
		System.out.println(cnt);
	}
}