1335A-Candies.cpp

#include <iostream>
#include<set>
using namespace std;

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
    int n;
    cin>>n;
    if(n%2==0)
    cout<<(n-2)/2<<endl;
    else
    cout<<(n-1)/2<<endl;
    }
}