Project Euler #1: Multiples of 3 and 5

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static long ans(long n){
        //n * (n - 1)/2
        long three = 0, first = 0, five = 0, second = 0, extra = 0, third = 0;
        if(n%3 == 0){
            three = n/3;
            first = 3*((three * (three - 1))/2);
        }else{
            three = n/3;
            first = 3*((three * (three + 1))/2);
        }

        if(n%5 == 0){
            five = n/5;
            second = 5*((five * (five - 1))/2);
        }else{
            five = n/5;
            second = 5*((five * (five + 1))/2);
        }

         if(n%15 == 0){
            extra = n/15;
            third = 15*((extra * (extra - 1))/2);
        }else{
            extra = n/15;
            third = 15*((extra * (extra + 1))/2);
        }
        
        

        return first + second - third;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int t = in.nextInt();
        for(int a0 = 0; a0 < t; a0++){
            long n = in.nextLong();
            System.out.println(ans(n));
        }
    }
}