#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t;
  cin >> t;
  while (t--) {
    long long n;
    cin >> n;
    if (n % 2 == 0)
      cout << (n - 1) / 2 << "\n";
    else
      cout << (n / 2) << "\n";
  }
}
