This is my program so far, it wants to print an upside down right triangle until "6 5 4" is printed. I can't seemto get it to 6 5 4 much less stop it

This is my program so far, it wants to print an upside down right triangle until "6 5 4" is printed. I can't seem to get it to 6 5 4 much less stop it

import java.util.Scanner;

public class Lab16C {

private int num;

public static void main(String[ ] args) 
{
    Lab16C lab = new Lab16C( );
    lab.input();    // Read rom the keyboard
    lab.output();   // Display output
}

public void input() {
    Scanner reader = new Scanner(System.in);
    System.out.print("Enter a number: ");
    num = reader.nextInt();
}

public void output(){
    for(int y = 0 ; y < num ; y++)
    {
        for(int x  = num ; x >= 4; x--)
            System.out.print(x + " ");
            num = num -1;
        System.out.println ();  
    }
}

}