A B Variations length N

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.TreeSet;

public class VariationsBrute {

    public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int number = Integer.parseInt(br.readLine());

        String inp = br.readLine();

        inp = inp.replace(" ", "");
        brute(inp, number, new StringBuffer());
        tSet.forEach(System.out::println);
    }
    static TreeSet tSet = new TreeSet();

    static void brute(String input, int depth, StringBuffer output) {
        if (depth == 0) {
            tSet.add(output.toString());
        } else {
            for (int i = 0; i < input.length(); i++) {
                output.append(input.charAt(i));
                brute(input, depth - 1, output);
                output.deleteCharAt(output.length() - 1);
            }
        }
    }
}