填空题

import java.util.^*;
public class LetterASort
public static void main (String args [])
ArrayList ＜String＞ strings = new ArrayList＜String＞ () ;
strings.add("aAaA") ;
strings.add ("AaA") ;
strings.add("aAa") ;
strings.add ("AAaa") ;
Collection.sort (strings) ;
for(Stirng s:strings) System.out.print (s+" ");


输出的结果是______.