#include <bits/stdc++.h>
#define ll long long
#define endll '\n';
#define pb push_back
#define all(v) v.begin(), v.end()
using namespace std;


const int mod = 1e9 + 7, N = 1e6;
 
void solve()
{
  int n; cin >> n;
  n = (n + 1) / 2;
  n--;
  cout << n << endll;
}

int32_t main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  int t = 1;
  cin >> t;
  while (t--) {
  solve();
}
 return 0;
}