#include <bits/stdc++.h>
using namespace std;
 
int sum(int n)
{
    return (n-1)* n/2;
}
int main()
{
    int t;
    cin >> t;
 
    while(t--){
        int a;
        cin >> a;
 
        int result = sum(a);
        cout << result << endl;
    }
 
    return 0;
}