#include <bits/stdc++.h>
using namespace std;
namespace mine {
long long qread() {
  long long ans = 0, f = 1;
  char c = getchar();
  while (c < '0' or c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while ('0' <= c and c <= '9') ans = ans * 10 + c - '0', c = getchar();
  return ans * f;
}
void write(long long num) {
  if (num < 0) putchar('-'), num = -num;
  if (num >= 10) write(num / 10);
  putchar('0' + num % 10);
}
void write1(long long num) {
  write(num);
  putchar(' ');
}
void write2(long long num) {
  write(num);
  putchar('\n');
}
template <typename T>
void chmax(T &x, const T y) {
  x = (x > y ? x : y);
}
template <typename T>
void chmin(T &x, const T y) {
  x = (x < y ? x : y);
}
long long gcd(long long x, long long y) { return y ? gcd(y, x % y) : 0; }
const int INF = 0x3f3f3f3f;
const int MOD = 998244353;
inline int mm(const int x) { return x >= MOD ? x - MOD : x; }
inline long long qpower(long long x, long long e) {
  long long ans = 1;
  while (e) {
    if (e & 1) ans = ans * x % MOD;
    x = x * x % MOD;
    e >>= 1;
  }
  return ans;
}
long long invm(long long x) { return qpower(x, MOD - 2); }
const int N = 1e6 + 10;
char str[N];
int fl[N], fr[N];
void main() {
  scanf("%s", str + 1);
  int n = strlen(str + 1);
  for (int i = 1; i <= n; i++) fl[i] = i - 1, fr[i] = i + 1;
  fr[n] = 0;
  int now = 1;
  while (fr[now]) {
    if (str[now] == 'S' and str[fr[now]] == 'T') {
      int x = fl[now], y = fr[fr[now]];
      fl[y] = x;
      fr[x] = y;
      now = x;
    } else
      now = fr[now];
  }
  int cnt = 1;
  while (fl[now]) cnt++, now = fl[now];
}
};  // namespace mine
int main() {
  srand(time(0));
  mine::main();
}
