#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MOD = 1e9 + 7;
const double pi = 3.14159265358979323846;
const int inf = 2e9;
const ll INF = 1e18;
using P = pair<int, int>;
int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int main() {
  cin.tie(0), cout.tie(0);
  ios::sync_with_stdio(false);
  string s;
  cin >> s;
  int cs = inf, ct = 0, ss = 0, tt = 0;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'S') {
      cs = min(cs, i);
    } else {
      ct = max(ct, i);
    }
  }
  for (int i = cs; i <= ct; i++) {
    if (s[i] == 'S') {
      ss++;
    } else {
      tt++;
    }
  }
  cout << s.size() - min(ss, tt) * 2 << endl;
}
