import java.util.Arrays;
import java.io.BufferedWriter;
import java.util.InputMismatchException;
import java.io.InputStream;
import java.util.NoSuchElementException;
import java.io.OutputStreamWriter;
import java.math.BigInteger;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Writer;
import java.io.IOException;

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

class TaskA {
    public void solve(int testNumber, MyScanner in, MyPrintWriter out) {
        String s = in.next();
        int res = 0;
        int depth = 0;
        for(char c:s.toCharArray()){
            if(c=='S'){
                depth++;
            }else{
                if(depth<=0){
                    res++;
                }else{
                    depth--;
                }
            }
        }
        res+=depth;
        out.println(res);
    }
}

class MyScanner {
    private final InputStream in;

    public MyScanner(InputStream in) {
        this.in = in;
    }

    private static final int BUFSIZE = 65536;
    int bufLen;
    int bufPtr;
    byte[] buf = new byte[BUFSIZE];

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

    private char[] strBuf = new char[BUFSIZE];

    public String next() {
        int strLen = 0;
        int c;
        do {
            c = read();
            if (c == -1) throw new NoSuchElementException();
        } while (Character.isWhitespace(c));
        do {
            if (strLen + 1 >= strBuf.length) {
                char[] tmp = new char[strBuf.length * 2];
                System.arraycopy(strBuf, 0, tmp, 0, strBuf.length);
                strBuf = tmp;
            }
            strBuf[strLen++] = (char) c;
            c = read();
        } while (c != -1 && !Character.isWhitespace(c));
        return new String(strBuf, 0, strLen);
    }

}

class MyPrintWriter {
    PrintWriter out;

    public MyPrintWriter(OutputStream outputStream) {
        out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
    }

    public void println(int a) {
        out.println(a);
    }

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

}

