import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {

  public static void main(String[] args) {
    FastScanner fs = new FastScanner();
    String s = fs.next();
    int maxCount = 0;
    int idx = 0;
    while (idx < 3) {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    }
    System.out.println(maxCount);
  }

  static class FastScanner {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");

    String next() {
      while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    int nextInt() {
      return Integer.parseInt(next());
    }

    int[] readArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    }

    long nextLong() {
      return Long.parseLong(next());
    }
  }
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main {

  public static void main(String[] args) {
    FastScanner fs = new FastScanner();
    String s = fs.next();
    int maxCount = 0;
    int idx = 0;
    while (idx < 3) {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    }
    System.out.println(maxCount);
  }

  static class FastScanner {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");

    String next() {
      while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    int nextInt() {
      return Integer.parseInt(next());
    }

    int[] readArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    }

    long nextLong() {
      return Long.parseLong(next());
    }
  }
} Main public static void main(String[] args) {
    FastScanner fs = new FastScanner();
    String s = fs.next();
    int maxCount = 0;
    int idx = 0;
    while (idx < 3) {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    }
    System.out.println(maxCount);
  } main {
    FastScanner fs = new FastScanner();
    String s = fs.next();
    int maxCount = 0;
    int idx = 0;
    while (idx < 3) {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    }
    System.out.println(maxCount);
  } FastScanner fs = new FastScanner(); fs new FastScanner() String s = fs.next(); s fs.next() fs.next fs int maxCount = 0; maxCount 0 int idx = 0; idx 0 while (idx < 3) {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    } idx < 3 idx 3 {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    } int start = idx; start idx while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      } idx < 3 && s.charAt(idx) == 'R' idx < 3 idx 3 s.charAt(idx) == 'R' s.charAt(idx) s.charAt s idx 'R' {
        idx++;
      } idx++ idx maxCount = Math.max(maxCount, idx - start) maxCount Math.max(maxCount, idx - start) Math.max Math maxCount idx - start idx start idx++ idx System.out.println(maxCount) System.out.println System.out System System.out maxCount String[] args args static class FastScanner {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");

    String next() {
      while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    int nextInt() {
      return Integer.parseInt(next());
    }

    int[] readArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    }

    long nextLong() {
      return Long.parseLong(next());
    }
  } FastScanner BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) StringTokenizer st = new StringTokenizer(""); st new StringTokenizer("") String next() {
      while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    } next {
      while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    } while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      } !st.hasMoreTokens() st.hasMoreTokens() st.hasMoreTokens st {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      } try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        } catch (IOException e) {
          e.printStackTrace();
        } IOException e {
          e.printStackTrace();
        } e.printStackTrace() e.printStackTrace e {
          st = new StringTokenizer(br.readLine());
        } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st int nextInt() {
      return Integer.parseInt(next());
    } nextInt {
      return Integer.parseInt(next());
    } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next int[] readArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    } readArray {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    } int[] a = new int[n]; a new int[n] n for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
        a[i] = nextInt();
      } {
        a[i] = nextInt();
      } a[i] = nextInt() a[i] a i nextInt() nextInt return a; a int n n long nextLong() {
      return Long.parseLong(next());
    } nextLong {
      return Long.parseLong(next());
    } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next public class Main {

  public static void main(String[] args) {
    FastScanner fs = new FastScanner();
    String s = fs.next();
    int maxCount = 0;
    int idx = 0;
    while (idx < 3) {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    }
    System.out.println(maxCount);
  }

  static class FastScanner {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");

    String next() {
      while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    int nextInt() {
      return Integer.parseInt(next());
    }

    int[] readArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    }

    long nextLong() {
      return Long.parseLong(next());
    }
  }
} public class Main {

  public static void main(String[] args) {
    FastScanner fs = new FastScanner();
    String s = fs.next();
    int maxCount = 0;
    int idx = 0;
    while (idx < 3) {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    }
    System.out.println(maxCount);
  }

  static class FastScanner {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");

    String next() {
      while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    int nextInt() {
      return Integer.parseInt(next());
    }

    int[] readArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    }

    long nextLong() {
      return Long.parseLong(next());
    }
  }
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {

  public static void main(String[] args) {
    FastScanner fs = new FastScanner();
    String s = fs.next();
    int maxCount = 0;
    int idx = 0;
    while (idx < 3) {
      int start = idx;
      while (idx < 3 && s.charAt(idx) == 'R') {
        idx++;
      }
      maxCount = Math.max(maxCount, idx - start);
      idx++;
    }
    System.out.println(maxCount);
  }

  static class FastScanner {

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");

    String next() {
      while (!st.hasMoreTokens()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      return st.nextToken();
    }

    int nextInt() {
      return Integer.parseInt(next());
    }

    int[] readArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++) {
        a[i] = nextInt();
      }
      return a;
    }

    long nextLong() {
      return Long.parseLong(next());
    }
  }
}
