#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
void c_p_c() {}
int ans(string second) {
  stack<char> stack;
  int i = 0;
  while (i < second.size()) {
    if (stack.empty()) {
      stack.push(second[i]);
      i++;
    } else {
      char ch = stack.top();
      if ((ch == 'B' and second[i] == 'B') or
          (ch == 'A' and second[i] == 'B')) {
        stack.pop();
        i++;
      } else {
        stack.push(second[i]);
        i++;
      }
    }
  }
  return stack.size();
}
int main() {
  long long i, n, m, k, c = 0, sum = 0;
  int p = 0;
  c_p_c();
  int t;
  cin >> t;
  while (t--) {
    string second;
    cin >> second;
    cout << ans(second) << "\n";
  }
  return 0;
}
