#include <bits/stdc++.h>
using namespace std;
int slv_by_payel(int n)
{
    int n1 = n - 1;
    int strt = 1,pair = 0;
    while(strt < n1)
    {
        pair++;
        n1--;
        strt++;
    }
    
    return pair;
}
int main()
{
    int tc;
    cin>>tc;
    while(tc--)
    {
        int n;
        cin>>n;
        int reslt = slv_by_payel(n);
        cout<<reslt<<endl;
    }
 
    return 0;
}