//#include <bits/stdc++.h>
//#include <stdio.h>
#include<iostream>
#include<cstdio>
#include<bitset>
#include<algorithm>
#include<vector>
#include<list>
#include<queue>
#include<stack>
#include<string>
#include<string.h>
#include<cmath>
#include<utility>
#include<functional>
#include<map>
#include<set>
#include<cctype>
#include<fstream>
#include <numeric>
#include <iomanip>
 
#define FOR(i, a, b) for( int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for( int i=(a);i>=(b);i--)
#define LFOR(i, a, b) for( long long int i=(a);i<=(b);i++)
#define LRFOR(i, a, b) for(long long int i=(a);i>=(b);i--)
#define MOD 1000000007
using namespace std;
using ll=long long;
constexpr ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
constexpr ll lcm(ll a,ll b){return a*b/gcd(a,b);}
 
int main() {

string N;
int n=0;
int nmax=0;
int ans=0;
  cin >> N;

  for(int i=0;i<N.size;i++){
    if(N[i]=='S'){
      n++;
      if(n>nmax){nmax=n;}
    }else{
      n--;
    }
  }



 
  cout << n*2<< endl;
  return 0;
}