#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using pii = pair<int, int>;
using ul = unsigned long;
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
ll GCD(ll a, ll b) { return b ? GCD(b, a % b) : a; }
ll LCM(ll a, ll b) { return a / GCD(a, b) * b; }
const int dy[] = {0, 1, 0, -1, -1, 1, 1, -1};
const int dx[] = {1, 0, -1, 0, 1, 1, -1, -1};
inline bool inside(int y, int x, int H, int W) {
  return (y >= 0 && x >= 0 && y < H && x < W);
}
const int INF = 1e9;
const int MOD = 1e9 + 7;
const ll LINF = 1e18;
signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  string s;
  cin >> s;
  int ls = 0, lt = 0;
  for (int i = (int)(0); i < (int)(s.size() - 1); ++i) {
    if (s[i] == 'S') {
      if (s[i + 1] == 'S') {
        ls++;
      } else {
        i++;
      }
    } else {
      if (ls > 0)
        ls--;
      else
        lt++;
    }
  }
  if (s[s.size() - 1] == 'S') ls++;
  cout << lt + ls << endl;
}
