/*
Bismillahir Rahmanir Rahim
(In the name of Allah)

@Author Muhammad Nadim
*/

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define all(x) x.begin(), x.end()
#define allr(x) x.rbegin(), x.rend()
#define CheckBit(x, k) (x & (1LL << k))
#define SetBit(x, k) (x |= (1LL << k))
#define ClearBit(x, k) (x &= ~(1LL << k))
#define LSB(mask) __builtin_ctzll(mask)
#define MSB(mask) 63 - __builtin_clzll(mask)
#define print(x) cout << #x << " : " << x << endl
#define error1(x) cerr << #x << " = " << (x) << endl
#define coutall(v)         \
    for (auto &it : v)     \
        cout << it << ' '; \
    cout << endl
#define Abid_52                  \
    ios::sync_with_stdio(false); \
    cin.tie(0), cin.tie(0)
#define error2(a, b) cerr << "( " << #a << " , " << #b << " ) = ( " << (a) << " , " << (b) << " )\n"
#define UNIQUE(x) sort(all(x)), x.erase(unique(all(x)), x.end()), x.shrink_to_fit()
template <typename T, typename U>
T ceil(T x, U y) { return (x > 0 ? (x + y - 1) / y : x / y); }
template <typename T, typename U>
T floor(T x, U y) { return (x > 0 ? x / y : (x - y + 1) / y); }

#define ld long double
#define nl '\n'
#define pi acos(-1.0)
#define sp(n) fixed << setprecision(n)
#define MNTDH_18                      \
    ios_base::sync_with_stdio(false); \
    cin.tie(NULL);
#define yes cout << "YES" << "\n"
#define no cout << "NO" << "\n"
// #define all(v) v.begin(), v.end()
#define CheckBit(x, k) (x & (1LL << k))
#define SetBit(x, k) (x |= (1LL << k))
#define ClearBit(x, k) (x &= ~(1LL << k))
#define LSB(mask) __builtin_ctzll(mask)
#define MSB(mask) 63 - __builtin_clzll(mask)

// template <typename T, typename U>
// T ceil(T x, U y) { return (x > 0 ? (x + y - 1) / y : x / y); }
// template <typename T, typename U>
// T floor(T x, U y) { return (x > 0 ? x / y : (x - y + 1) / y); }

// typedef  __int128 lll;
typedef struct rafi
{
    ll type;
    ll idx1;
    ll idx2;
} R;

typedef struct sajeeb
{
    ll val1;
    ll val2;
} S;

typedef struct ohi
{
    ll l;
    ll r;
    ll u;
    ll d;
    int val;
} O;

const int N = 2e5 + 7, M = 1073741824, N1 = 64;
bool isPowerOfTwo(int n)
{
    if (n == 0)
        return false;

    return (ceil(log2(n)) == floor(log2(n)));
}
void sF()
{
    ll n;
    cin>>n;
    cout<<((n-1)>>1)<<nl;
}

int main()
{
    MNTDH_18
    // pow2();

    ll tc = 1, x = 1;
    cin >> tc;

    while (tc--)
    {
        // cout << "Case " << x++ << ": ";
        sF();
    }

    return 0;
}