import java.util.Scanner; class test{     public static void main(String args[]){                    Scanner Scanner = new Scanner(System.in);          String a,b,c,x;                              a = Scanner.next();          b = Scanner.next();          c = Scanner.next();                    System.out.println("hello, "+a);          System.out.println("hello, "+b);          System.out.println("hello, "+c);                        } } ------------------------------------------------------ 我用別的線上網頁編譯可以編譯出來,但是為什麼這邊就一直顯示NA