import java.util.*;

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

    int max = 0;
    int tmp = 0;

    for (int i=0; i<s.length(); i++)
    {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    }

    System.out.println(max);

  }
} import java.util.*; util.* java public class Main
{
  public static void main(String[] args)
  {
  	Scanner sc = new Scanner(System.in);
    String s = sc.next();

    int max = 0;
    int tmp = 0;

    for (int i=0; i<s.length(); i++)
    {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    }

    System.out.println(max);

  }
} Main public static void main(String[] args)
  {
  	Scanner sc = new Scanner(System.in);
    String s = sc.next();

    int max = 0;
    int tmp = 0;

    for (int i=0; i<s.length(); i++)
    {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    }

    System.out.println(max);

  } main {
  	Scanner sc = new Scanner(System.in);
    String s = sc.next();

    int max = 0;
    int tmp = 0;

    for (int i=0; i<s.length(); i++)
    {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    }

    System.out.println(max);

  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.next(); s sc.next() sc.next sc int max = 0; max 0 int tmp = 0; tmp 0 for (int i=0; i<s.length(); i++)
    {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    } int i=0; int i=0; i 0 i<s.length() i s.length() s.length s i++ i++ i {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    } {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    } if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0; s.charAt(i) == 'R' s.charAt(i) s.charAt s i 'R' tmp++ tmp tmp = 0 tmp 0 if (tmp > max)
            max = tmp; tmp > max tmp max max = tmp max tmp System.out.println(max) System.out.println System.out System System.out max String[] args args public class Main
{
  public static void main(String[] args)
  {
  	Scanner sc = new Scanner(System.in);
    String s = sc.next();

    int max = 0;
    int tmp = 0;

    for (int i=0; i<s.length(); i++)
    {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    }

    System.out.println(max);

  }
} public class Main
{
  public static void main(String[] args)
  {
  	Scanner sc = new Scanner(System.in);
    String s = sc.next();

    int max = 0;
    int tmp = 0;

    for (int i=0; i<s.length(); i++)
    {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    }

    System.out.println(max);

  }
} Main
import java.util.*;

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

    int max = 0;
    int tmp = 0;

    for (int i=0; i<s.length(); i++)
    {
        if (s.charAt(i) == 'R')
            tmp++;
        else
            tmp = 0;
        
        if (tmp > max)
            max = tmp;
    }

    System.out.println(max);

  }
}