import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        String[] ar = str.split("");
        int c = 0;
        String r = "R";
        if (ar[0].equals(r)) {
            c = c + 1;
        } else {
            c = c;
        }
        if (ar[1].equals(r)) {
            c = c + 1;
        } else {
            c = c;
        }
        if (ar[2].equals(r)) {
            c = c + 1;
        } else {
            c = c;
        }
        if (c == 1 || c == 3 || c == 0) {
            System.out.println(c);
        } else if ( c == 2 && ar[0].equals(r) && ar[2].equals(r)) {
            System.out.println(1);
        } else {
            System.out.println(2);
        }
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz