import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char[] s = sc.nextLine().toCharArray();
        sc.close();

        int cnt = 0;
        for(char c: s) {
            if(c == 'R') cnt++;
        }
        if(cnt == 2 && s[1] == 'S') cnt = 1;
        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);
        char[] s = sc.nextLine().toCharArray();
        sc.close();

        int cnt = 0;
        for(char c: s) {
            if(c == 'R') cnt++;
        }
        if(cnt == 2 && s[1] == 'S') cnt = 1;
        System.out.println(cnt);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char[] s = sc.nextLine().toCharArray();
        sc.close();

        int cnt = 0;
        for(char c: s) {
            if(c == 'R') cnt++;
        }
        if(cnt == 2 && s[1] == 'S') cnt = 1;
        System.out.println(cnt);
    } main {
        Scanner sc = new Scanner(System.in);
        char[] s = sc.nextLine().toCharArray();
        sc.close();

        int cnt = 0;
        for(char c: s) {
            if(c == 'R') cnt++;
        }
        if(cnt == 2 && s[1] == 'S') cnt = 1;
        System.out.println(cnt);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char[] s = sc.nextLine().toCharArray(); s sc.nextLine().toCharArray() sc.nextLine().toCharArray sc.nextLine() sc.nextLine sc sc.close() sc.close sc int cnt = 0; cnt 0 for(char c: s) {
            if(c == 'R') cnt++;
        } char c s {
            if(c == 'R') cnt++;
        } {
            if(c == 'R') cnt++;
        } if(c == 'R') cnt++; c == 'R' c 'R' cnt++ cnt if(cnt == 2 && s[1] == 'S') cnt = 1; cnt == 2 && s[1] == 'S' cnt == 2 cnt 2 s[1] == 'S' s[1] s 1 'S' cnt = 1 cnt 1 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);
        char[] s = sc.nextLine().toCharArray();
        sc.close();

        int cnt = 0;
        for(char c: s) {
            if(c == 'R') cnt++;
        }
        if(cnt == 2 && s[1] == 'S') cnt = 1;
        System.out.println(cnt);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char[] s = sc.nextLine().toCharArray();
        sc.close();

        int cnt = 0;
        for(char c: s) {
            if(c == 'R') cnt++;
        }
        if(cnt == 2 && s[1] == 'S') cnt = 1;
        System.out.println(cnt);
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char[] s = sc.nextLine().toCharArray();
        sc.close();

        int cnt = 0;
        for(char c: s) {
            if(c == 'R') cnt++;
        }
        if(cnt == 2 && s[1] == 'S') cnt = 1;
        System.out.println(cnt);
    }
}
