class Arstr{
    private int pos ;
    private String str;
    public Arstr(Integer i,String s1) {
        this.pos = i;
        this.str=s1;
    }
    public int getpos() {
        return this.pos;
    }
    public String getstr() {
        return this.str;
    }
}

class Result {

    /*
     * Complete the 'countSort' function below.
     *
     * The function accepts 2D_STRING_ARRAY arr as parameter.
     */

    public static void countSort(List<List<String>> arr) {
    // Write your code here
    List<Arstr> res = new ArrayList<>();
        
         Comparator<Arstr> comp = new Comparator<Arstr>(){
             
                @Override
                public int compare(Arstr o1, Arstr o2) {
                    
                    return (o1.getpos() - o2.getpos());
                }
         };
        
        for(int i=0;i<arr.size();i++) {
            if(i<arr.size()/2) {
                res.add(new Arstr(Integer.valueOf(arr.get(i).get(0)),"-"));
            }
            else {
            res.add(new Arstr(Integer.valueOf(arr.get(i).get(0)),arr.get(i).get(1)));
            }
        }
        Collections.sort(res,comp);
        for(Arstr a:res) {
            System.out.print(a.getstr()+" ");
        }
    }

}