给出下列【代码】注释标注的代码的输出结果。import java.util.*;public class E {public static void main(String args[]) {TreeMap treemap= new TreeMap();treemap.put(12,"d");treemap.put(1,"b");treemap.put(5,"r");treemap.put(3,"i");Collection cn =treemap.values();Iterator iterator = cn.iterator();String s1 =iterator.next();String s2 =iterator.next();String s3 =iterator.next();String s4 =iterator.next();System.out.printf("%s%s%s%s", s1,s2,s3,s4); //【代码】}}