#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define dub double
#define ull unsigned long long
#define CY cout << "YES\n"
#define CN cout << "NO\n"
#define allok() (ios_base:: sync_with_stdio(false),cin.tie(NULL));
//** Number theory --> begin
ll gcd ( ll a, ll b )
{
if ( b == 0 ) return a;
else return gcd ( b, a%b );
}
ll lcm ( ll a, ll b )
{
return (a*b) / gcd(a, b);
}
const ll m = 1e9;
ll mod ( ll a )
{
return ( (a%m + m) % m );
}
ll madd ( ll a, ll b )
{
return mod ( mod(a)+mod(b) );
}
ll mmul ( ll a, ll b )
{
return mod ( mod(a)*mod(b) );
}
//** Number theory --> end
//** Bitwise --> begin
// swap ( x, y ) --> x=x^y, y=x^y, x=x^y
// if x=a then x=b // if x=b then x=a --> x=a^b^x
// a+b=(a^b)+2(a&b)
// a+b=(a|b)+(a&b)
bool checkkthbit ( ll x, ll k )
{
return (x & (1<<k)); // k'th bit set or not
}
ll setkthbit1 ( ll x, ll k )
{
return (x | (1<<k)); // make k'th bit 1;
}
ll setkthbit0 ( ll x, ll k )
{
return (x &~ (1<<k)); // make k'th bit 0;
}
ll mulnumby2powk ( ll x, ll k )
{
return (x<<k); // x*(pow(2,k))
}
ll divnumby2powk ( ll x, ll k )
{
return (x>>k); // x/pow(2,k)
}
int noofsetbitint ( int x )
{
return __builtin_popcount(x); // int set bit count
}
ll noofsetbitll ( ll x )
{
return __builtin_popcountll(x); // ll set bit count
}
ll togglekthbit ( ll x, ll k )
{ // if k = 0 then k = 1
return (x ^ ( 1<<k )); // if k = 1 then k = 0
}
bool powerof2 ( ll x )
{
return (x && !(x&(x-1))); // power of 2 checking
}
//** Bitwise --> end
void oddsum ( ll a[], ll x )
{
ll mio = INT_MAX;
bool odd = false;
ll sm = 0;
for ( ll i=0; i<x; i++ ) {
if ( a[i] > 0 ) sm += a[i];
if ( (a[i] & 1) ) {
odd = true;
if ( mio > abs ( a[i] ) ) {
mio = abs ( a[i] );
}
}
}
if ( !(sm & 1) ) sm -= mio;
cout << sm << endl;
}
void solve ( )
{
ll x;
cin >> x;
cout << (x-1)/2 << endl;
}
int main() {
// allok();
ll tc, cnt=1;
cin >> tc;
while ( tc-- ) solve();
return 0;
}