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