Cannot make a static reference to the non-static field "n"

Question

I just start learning Java and I try to make my very first code due to the classic "hello world" but I also put a small modification.

 public class example {
         int n= 7;
 public static void main (String[] args){
         System.out.println(" the number here is  "+ n);}}

It doesn't work. I looking for some lights. Thank in advance