using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Runtime.CompilerServices;
using ll=System.Int64;

public class Contest
{
	static void Swap1<T>(ref T a, ref T b) { T t = a; a = b; b = t; }
	static void Swap2<T>(ref T a, ref T b) where T : IComparable { if (a.CompareTo(b)==1) Swap1(ref a, ref b); }  // b の方が小さければ交換
	static bool Chmin<T>(ref T a, T b) where T : IComparable { if (a.CompareTo(b)== 1) { a = b; return true; } return false; }  // b の方が小さければ a を更新
	static bool Chmax<T>(ref T a, T b) where T : IComparable { if (a.CompareTo(b)==-1) { a = b; return true; } return false; }  // b の方が大きければ a を更新
	static T[][] InitMat<T>(long len1, long len2, T val){ T[][] m = new T[len1][]; for (int i = 0; i < m.Length; i++) m[i] = Enumerable.Repeat(val, (int)len2).ToArray(); return m; }
	static T[][][] InitMat<T>(long len1, long len2, long len3, T val){ T[][][] m = new T[len1][][]; for (int i = 0; i < m.Length; i++) m[i] = InitMat(len2,len3,val); return m; }
	public const long MOD1 = 1000000007; // 10^9+7
	public const double EPS1 = 1e-8;

	public static void Main() {
		Solve_A();
 	}

	public static void Solve_A() {
		string s;
		MyIO.ReadMulti(out s);

		ll ans = 0;
		for (int i = s.Length-1; 0<=i; i--)
		{
			if(s[i]=='S'){
				ans++;
			}else{
				break;
			}
			
		}

		MyIO.WriteMulti(ans*2);

	}
	public static void Solve_B() {
		ll  n;
		MyIO.ReadMulti(out n);
		VT<ll,ll>[] lrl;
		MyIO.ReadLines(n, out lrl);


		VT<ll,ll,ll>[] lri = new VT<ll, ll, ll>[n];
		for (int i = 0; i < n; i++)
		{
			lri[i] = new VT<ll, ll, ll>(lrl[i].Item1,lrl[i].Item2,i);
		}

		Array.Sort(lri,(x,y)=>(x.Item1.CompareTo(y.Item1)));

		VT<ll,ll>[] ll = new VT<ll, ll>[n+2];
		VT<ll,ll>[] rl = new VT<ll, ll>[n+2];
		ll[0]= new VT<ll, ll>(1,1000000000);
		rl[n+1]= new VT<ll, ll>(1,1000000000);

		long ans = 0;

/*
		for (int i = 1; i <= n; i++)
		{
			ll[i]= new VT<ll, ll>(Math.Max(lrl[i-1].Item1,ll[i-1].Item1),Math.Min(lrl[i-1].Item2,ll[i-1].Item2));
		}
		for (int i = (int)n; 0<i; i--)
		{
			rl[i]= new VT<ll, ll>(Math.Max(lrl[i-1].Item1,rl[i+1].Item1),Math.Min(lrl[i-1].Item2,rl[i+1].Item2));
		}

		for (int i = 1; i < n-1; i++)
		{
			ll v = ((ll[i].Item2>=ll[i].Item1)?(ll[i].Item2-ll[i].Item1+1):0) + ((rl[i+1].Item2>=rl[i+1].Item1)?(rl[i+1].Item2-rl[i+1].Item1+1):0);
			Chmax(ref ans, v);
		}
*/
		ll l2 = lri[n-1].Item1;
		ll r2 = lri[n-1].Item2;
		ll i2 = lri[n-1].Item3;
		ll i2a = lri[0].Item3;
		Array.Sort(lri,(x,y)=>(x.Item2.CompareTo(y.Item2)));		
		ll l1 = lri[0].Item1;
		ll r1 = lri[0].Item2;
		ll i1 = lri[0].Item3;
		if(i1==i2){
		 l1 = lri[1].Item1;
		 r1 = lri[1].Item2;
		 i1 = lri[1].Item3;
		}
		ll i1a = lri[n-1].Item3;


		if(i2a==i1a){
			for (int i = 0; i < n; i++)
			{
				if(lri[i].Item3==i1a) {
				l2 = lri[i].Item1;
				r2 = lri[i].Item2;
				}else{
				l1 = l1<lri[i].Item1?lri[i].Item1:l1;
				r1 = r1<lri[i].Item2?r1:lri[i].Item2;
				}
			}

		}else{
			for (int i = 0; i < n; i++)
			{
				ll tl1 = l1<lrl[i].Item1?lrl[i].Item1:l1;
				ll tl2 = l2<lrl[i].Item1?lrl[i].Item1:l2;
				ll tr1 = r1<lrl[i].Item2?r1:lrl[i].Item2;
				ll tr2 = r2<lrl[i].Item2?r2:lrl[i].Item2;
				ll d1 = Math.Max(r1-l1,-1)-Math.Max(tr1-tl1,-1);
				ll d2 = Math.Max(r2-l2,-1)-Math.Max(tr2-tl2,-1);
				if(d2<d1){
					l2 = tl2;
					r2 = tr2;
				}else{
					l1 = tl1;
					r1 = tr1;	
				}
			}


			}
			ans = Math.Max(r1-l1,-1)+Math.Max(r2-l2,-1)+2;
		MyIO.WriteMulti(ans);

	}
	public static void Solve_C() {
		ll  n, m;
		MyIO.ReadMulti(out n, out m);



		long ans = 0;

		MyIO.WriteMulti(ans);

	}
	public static void Solve_D() {
		ll  n, m;
		MyIO.ReadMulti(out n, out m);



		long ans = 0;

		MyIO.WriteMulti(ans);

	}
	public static void Solve_E() {
		ll  n, m;
		MyIO.ReadMulti(out n, out m);



		long ans = 0;

		MyIO.WriteMulti(ans);

	}
	public static void Solve_F() {
		ll  n, m;
		MyIO.ReadMulti(out n, out m);



		long ans = 0;

		MyIO.WriteMulti(ans);

	}



	public static long Gcd(long a, long b) {
	    var v = new[] { a, b };
	    while (v[1] != 0) v = new[] { v[1], v[0] % v[1] };
	    return v[0];
	}









}


















#region MyIO

public struct VT<T, U>
{
	public T Item1; public U Item2;
    public VT(T a, U b) { Item1 = a; Item2 = b; }
}
public struct VT<T, U, V>
{
	public T Item1; public U Item2; public V Item3;
    public VT(T a, U b, V c) { Item1 = a; Item2 = b; Item3 = c; }
}
public struct VT<T, U, V, W>
{
	public T Item1; public U Item2; public V Item3; public W Item4;
    public VT(T a, U b, V c, W d) { Item1 = a; Item2 = b; Item3 = c; Item4 = d; }
}

public class Printer : System.IO.StreamWriter
{
	public override IFormatProvider FormatProvider { get { return System.Globalization.CultureInfo.InvariantCulture; } }
	public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
	public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
}
public static class MyIO
{
	private static char[] splitter = new char[] {' '};
	private static bool eq<T, U>() => typeof(T).Equals(typeof(U));
	private static T ct<T, U>(U a) => (T)Convert.ChangeType(a, typeof(T));
	private static T cv<T>(string s) =>
		eq<T, int>()    ? ct<T, int>(int.Parse(s))
	  : eq<T, long>()   ? ct<T, long>(long.Parse(s))
	  : eq<T, double>() ? ct<T, double>(double.Parse(s, System.Globalization.CultureInfo.InvariantCulture))
	  : eq<T, char>()   ? ct<T, char>(s[0])
						: ct<T, string>(s);
			
	public static string[] ReadMulti<T>(out T a) {
		var ar = Console.ReadLine().Split(splitter, StringSplitOptions.RemoveEmptyEntries); 
		a = cv<T>(ar[0]);
		return ar;
	}
	public static string[] ReadMulti<T, U>(out T a, out U b) {
		var ar = ReadMulti<T>(out a); 
        b = cv<U>(ar[1]);
		return ar;
	}
	public static string[] ReadMulti<T, U, V>(out T a, out U b, out V c) {
		var ar = ReadMulti<T, U>(out a, out b); 
        c = cv<V>(ar[2]);
		return ar;
	}
	public static string[] ReadMulti<T, U, V, W>(out T a, out U b, out V c, out W d) {
		var ar = ReadMulti<T, U, V>(out a, out b, out c); 
        d = cv<W>(ar[3]);
		return ar;
	}
	public static string[] ReadMulti<T, U, V, W, X>(out T a, out U b, out V c, out W d, out X e) {
		var ar = ReadMulti<T, U, V, W>(out a, out b, out c, out d); 
        e = cv<X>(ar[4]);
		return ar;
	}
	public static string[] ReadMulti<T, U, V, W, X, Y>(out T a, out U b, out V c, out W d, out X e, out Y f) {
		var ar = ReadMulti<T, U, V, W, X>(out a, out b, out c, out d, out e); 
        f = cv<Y>(ar[5]);
		return ar;
	}
	public static string[] ReadArray<T>(out T[] a) {		
		var ar = Console.ReadLine().Split(splitter, StringSplitOptions.RemoveEmptyEntries);
		a = ar.Select(cv<T>).ToArray();
		return ar;
	}		
	public static string[][] ReadLines<T>(long n, out T[] a) {
		a = new T[n];
		string[][] arr = new string[n][];
		for(int i=0; i<n; i++) arr[i] = ReadMulti(out a[i]);
		return arr;
	}
	public static string[][] ReadLines<T, U>(long n, out VT<T, U>[] a) {
		a = new VT<T, U>[n];
		string[][] arr = new string[n][];
		for(int i=0; i<n; i++) {
			T o; U p;
			arr[i] = ReadMulti(out o, out p);
			a[i] = new VT<T, U>(o, p);
		}
		return arr;
	}
	public static string[][] ReadLines<T, U, V>(long n, out VT<T, U, V>[] a) {
		a = new VT<T, U, V>[n];
		string[][] arr = new string[n][];
		for(int i=0; i<n; i++) {
			T o; U p; V q;
			arr[i] = ReadMulti(out o, out p, out q);
			a[i] = new VT<T, U, V>(o, p, q);
		}
		return arr;
	}
	public static string[][] ReadLines<T, U, V, W>(long n, out VT<T, U, V, W>[] a) {
		a = new VT<T, U, V, W>[n];
		string[][] arr = new string[n][];
		for(int i=0; i<n; i++) {
			T o; U p; V q; W r;
			arr[i] = ReadMulti(out o, out p, out q, out r);
			a[i] = new VT<T, U, V, W>(o, p, q, r);
		}
		return arr;
	}
	public static string[][] ReadMatrix<T>(long n, out T[][] a) {
		a = new T[n][];
		string[][] arr = new string[n][];
		for(int i=0; i<n; i++) arr[i] = ReadArray(out a[i]);
		return arr;
	}

	private static void wwp(Action act){
		var sw = new Printer(Console.OpenStandardOutput()){AutoFlush = false};
		Console.SetOut(sw);
		act();
		Console.Out.Flush();
		sw.AutoFlush = true;
		Console.SetOut(sw);
	}
	private static string wfm(Type t) =>t.Equals(typeof(double)) ? "{0:F10}" : "{0}";
	public static void WriteMulti(params object[] a) {
		wwp(()=>{
			for(int i=0;i<a.Length;i++) {
				string fs = wfm(a[i].GetType()) + ((i<a.Length-1) ? " " : Environment.NewLine);
				Console.Write(fs, a[i]);
			}
		});
	}
	public static void WriteArray<T>(T[] a) {
		wwp(()=>{
			string fs = wfm(typeof(T));
			string fs1 = fs + " ";
			string fs2 = fs + Environment.NewLine;
			for(int i=0;i<a.Length;i++) Console.Write( ((i<a.Length-1) ? fs1 : fs2), a[i]);
		});
	}
	public static void WriteLines<T>(T[] a) {
		wwp(()=>{
			string fs = wfm(typeof(T)) + Environment.NewLine;
			foreach(T x in a) Console.Write(fs, x);
		});
	}


}

#endregion

