import java.io.*;
import java.util.InputMismatchException;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        ARainySeasonEditorial solver = new ARainySeasonEditorial();
        solver.solve(1, in, out);
        out.close();
    }

    static class ARainySeasonEditorial {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            String str = in.next();
            Character left = str.charAt(0);
            Character middle = str.charAt(1);
            Character right = str.charAt(2);
            if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            }
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return nextString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
}
 import java.io.*; io.* java import java.util.InputMismatchException; InputMismatchException java.util public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        ARainySeasonEditorial solver = new ARainySeasonEditorial();
        solver.solve(1, in, out);
        out.close();
    }

    static class ARainySeasonEditorial {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            String str = in.next();
            Character left = str.charAt(0);
            Character middle = str.charAt(1);
            Character right = str.charAt(2);
            if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            }
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return nextString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        ARainySeasonEditorial solver = new ARainySeasonEditorial();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        ARainySeasonEditorial solver = new ARainySeasonEditorial();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out InputReader in = new InputReader(inputStream); in new InputReader(inputStream) OutputWriter out = new OutputWriter(outputStream); out new OutputWriter(outputStream) ARainySeasonEditorial solver = new ARainySeasonEditorial(); solver new ARainySeasonEditorial() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class ARainySeasonEditorial {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            String str = in.next();
            Character left = str.charAt(0);
            Character middle = str.charAt(1);
            Character right = str.charAt(2);
            if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            }
        }

    } ARainySeasonEditorial public void solve(int testNumber, InputReader in, OutputWriter out) {
            String str = in.next();
            Character left = str.charAt(0);
            Character middle = str.charAt(1);
            Character right = str.charAt(2);
            if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            }
        } solve {
            String str = in.next();
            Character left = str.charAt(0);
            Character middle = str.charAt(1);
            Character right = str.charAt(2);
            if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            }
        } String str = in.next(); str in.next() in.next in Character left = str.charAt(0); left str.charAt(0) str.charAt str 0 Character middle = str.charAt(1); middle str.charAt(1) str.charAt str 1 Character right = str.charAt(2); right str.charAt(2) str.charAt str 2 if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            } left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R' left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R' left.charValue() == 'R' left.charValue() left.charValue left 'R' middle.charValue() == 'R' middle.charValue() middle.charValue middle 'R' right.charValue() == 'R' right.charValue() right.charValue right 'R' {
                out.println(3);
            } out.println(3) out.println out 3 if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            } (left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S') (left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S') left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S' left.charValue() == 'R' left.charValue() left.charValue left 'R' middle.charValue() == 'R' middle.charValue() middle.charValue middle 'R' right.charValue() == 'S' right.charValue() right.charValue right 'S' (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S') middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S' middle.charValue() == 'R' middle.charValue() middle.charValue middle 'R' right.charValue() == 'R' right.charValue() right.charValue right 'R' left.charValue() == 'S' left.charValue() left.charValue left 'S' {
                out.println(2);
            } out.println(2) out.println out 2 if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            } (left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S') (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R') (left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S') (left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S') left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S' left.charValue() == 'R' left.charValue() left.charValue left 'R' middle.charValue() == 'S' middle.charValue() middle.charValue middle 'S' right.charValue() == 'S' right.charValue() right.charValue right 'S' (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S') left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S' left.charValue() == 'S' left.charValue() left.charValue left 'S' middle.charValue() == 'R' middle.charValue() middle.charValue middle 'R' right.charValue() == 'S' right.charValue() right.charValue right 'S' (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R') left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R' left.charValue() == 'S' left.charValue() left.charValue left 'S' middle.charValue() == 'S' middle.charValue() middle.charValue middle 'S' right.charValue() == 'R' right.charValue() right.charValue right 'R' (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S') left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S' left.charValue() == 'R' left.charValue() left.charValue left 'R' right.charValue() == 'R' right.charValue() right.charValue right 'R' middle.charValue() == 'S' middle.charValue() middle.charValue middle 'S' {
                out.println(1);
            } out.println(1) out.println out 1 if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            } left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S' left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S' left.charValue() == 'S' left.charValue() left.charValue left 'S' middle.charValue() == 'S' middle.charValue() middle.charValue middle 'S' right.charValue() == 'S' right.charValue() right.charValue right 'S' {
                out.println(0);
            } out.println(0) out.println out 0 int testNumber testNumber InputReader in in OutputWriter out out static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void println(int i) {
            writer.println(i);
        }

    } OutputWriter private final PrintWriter writer; writer public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        } OutputWriter {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        } writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream))) writer new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream))) OutputStream outputStream outputStream public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        } OutputWriter {
            this.writer = new PrintWriter(writer);
        } this.writer = new PrintWriter(writer) this.writer this this.writer new PrintWriter(writer) Writer writer writer public void close() {
            writer.close();
        } close {
            writer.close();
        } writer.close() writer.close writer public void println(int i) {
            writer.println(i);
        } println {
            writer.println(i);
        } writer.println(i) writer.println writer i int i i static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return nextString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    } InputReader private InputStream stream; stream private byte[] buf = new byte[1024]; buf new byte[1024] 1024 private int curChar; curChar private int numChars; numChars private InputReader.SpaceCharFilter filter; filter public InputReader(InputStream stream) {
            this.stream = stream;
        } InputReader {
            this.stream = stream;
        } this.stream = stream this.stream this this.stream stream InputStream stream stream public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        } read {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        } if (numChars == -1) {
                throw new InputMismatchException();
            } numChars == -1 numChars -1 1 {
                throw new InputMismatchException();
            } throw new InputMismatchException(); new InputMismatchException() if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            } curChar >= numChars curChar numChars {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            } curChar = 0 curChar 0 try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                } catch (IOException e) {
                    throw new InputMismatchException();
                } IOException e {
                    throw new InputMismatchException();
                } throw new InputMismatchException(); new InputMismatchException() {
                    numChars = stream.read(buf);
                } numChars = stream.read(buf) numChars stream.read(buf) stream.read stream buf if (numChars <= 0) {
                    return -1;
                } numChars <= 0 numChars 0 {
                    return -1;
                } return -1; -1 1 return buf[curChar++]; buf[curChar++] buf curChar++ curChar public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        } nextString {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        } int c = read(); c read() read while (isSpaceChar(c)) {
                c = read();
            } isSpaceChar(c) isSpaceChar c {
                c = read();
            } c = read() c read() read StringBuilder res = new StringBuilder(); res new StringBuilder() do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c)); !isSpaceChar(c) isSpaceChar(c) isSpaceChar c {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                } Character.isValidCodePoint(c) Character.isValidCodePoint Character c {
                    res.appendCodePoint(c);
                } res.appendCodePoint(c) res.appendCodePoint res c c = read() c read() read return res.toString(); res.toString() res.toString res public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        } isSpaceChar {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        } if (filter != null) {
                return filter.isSpaceChar(c);
            } filter != null filter null {
                return filter.isSpaceChar(c);
            } return filter.isSpaceChar(c); filter.isSpaceChar(c) filter.isSpaceChar filter c return isWhitespace(c); isWhitespace(c) isWhitespace c int c c public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        } isWhitespace {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        } return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1 c == '\t' c == '\r' c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1 c == ' ' c ' ' c == '\n' c '\n' c == '\r' c '\r' c == '\t' c '\t' c == -1 c -1 1 int c c public String next() {
            return nextString();
        } next {
            return nextString();
        } return nextString(); nextString() nextString public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        } SpaceCharFilter public boolean isSpaceChar(int ch); isSpaceChar int ch ch public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        ARainySeasonEditorial solver = new ARainySeasonEditorial();
        solver.solve(1, in, out);
        out.close();
    }

    static class ARainySeasonEditorial {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            String str = in.next();
            Character left = str.charAt(0);
            Character middle = str.charAt(1);
            Character right = str.charAt(2);
            if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            }
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return nextString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        ARainySeasonEditorial solver = new ARainySeasonEditorial();
        solver.solve(1, in, out);
        out.close();
    }

    static class ARainySeasonEditorial {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            String str = in.next();
            Character left = str.charAt(0);
            Character middle = str.charAt(1);
            Character right = str.charAt(2);
            if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            }
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return nextString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
} Main
import java.io.*;
import java.util.InputMismatchException;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        ARainySeasonEditorial solver = new ARainySeasonEditorial();
        solver.solve(1, in, out);
        out.close();
    }

    static class ARainySeasonEditorial {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            String str = in.next();
            Character left = str.charAt(0);
            Character middle = str.charAt(1);
            Character right = str.charAt(2);
            if (left.charValue() == 'R' && middle.charValue() == 'R'
                    && right.charValue() == 'R') {
                out.println(3);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (middle.charValue() == 'R' && right.charValue() == 'R' && left.charValue() == 'S')) {
                out.println(2);
            } else if ((left.charValue() == 'R' && middle.charValue() == 'S' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'R' && right.charValue() == 'S')
                    || (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'R')
                    || (left.charValue() == 'R' && right.charValue() == 'R' && middle.charValue() == 'S')) {
                out.println(1);
            } else if (left.charValue() == 'S' && middle.charValue() == 'S' && right.charValue() == 'S') {
                out.println(0);
            }
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public String nextString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                if (Character.isValidCodePoint(c)) {
                    res.appendCodePoint(c);
                }
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next() {
            return nextString();
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
}

