请问在java中byte和int怎样才能一齐用？？

public class Hello{
 public static void main (String[] args){
    byte a = 1;
     int k;
     int s ;
     for (k = 1; k <= 8; k++){
         s = a * 2;
             a = a * 2;
         System.out.println(s);}
  }
在这程序中；怎么解决？？

public class Hello{
 public static void main (String[] args){
    byte a = 1;
     int k;
     int s ;
     for (k = 1; k <= 8; k++){
         s = a * 2;
             a = a * 2;
         System.out.println(s);}
  }
请教在这程序中怎么转换？？？

不明白··

谢谢···但是K的长度要《=8啊··