#include <bits/stdc++.h>
using namespace std;
const long long int INF = 1LL << 60;
const long long int Mod = 1000000007;
using ll = long long int;
using ci = const int;
using vi = vector<int>;
using Vi = vector<long long int>;
using P = pair<int, int>;
using PLL = pair<ll, ll>;
using matrix = vector<vector<ll>>;
template <class T>
bool chmax(T &former, const T &b) {
  if (former < b) {
    former = b;
    return true;
  }
  return false;
}
template <class T>
bool chmin(T &former, const T &b) {
  if (b < former) {
    former = b;
    return true;
  }
  return false;
}
template <class T>
T sqar(T x) {
  return x * x;
}
template <class T>
inline void princ(T x) {
  cout << x << " ";
};
template <class T>
inline void print(T x) {
  cout << x << "\n";
};
template <class T>
inline void Yes(T condition) {
  if (condition)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
template <class T>
inline void YES(T condition) {
  if (condition)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}
string x;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(30);
  cin >> x;
  priority_queue<ll, vector<ll>, greater<ll>> pqt;
  Vi s;
  for (ll i = 0; i < (ll)x.size(); i++) {
    if (x[i] == 'S') {
      s.push_back(i);
    } else {
      pqt.push(i);
    }
  }
  ll as = 0;
  while (!pqt.empty()) {
    ll idt = pqt.top();
    pqt.pop();
    ll ids = lower_bound((s).begin(), (s).end(), idt - 1) - s.begin();
    if (ids >= s.size()) ids--;
    if (ids < 0) continue;
    if (s[ids] > idt) ids--;
    if (ids < 0) continue;
    if (s[ids] < idt) {
      as++;
      s.erase(s.begin() + ids);
    }
  }
  print(x.size() - as * 2);
  return 0;
}
