package RecursionAndBacktracking;

import java.util.ArrayList;

import java.util.Scanner;

public class stringSubsequence {

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner sc = new Scanner(System.in);

String str = sc.next();

ArrayList<String> res = getSubSequence(str);

System.out.println(res);

}

private static ArrayList<String> getSubSequence(String str) {

// TODO Auto-generated method stub

if(str.length() == 0) {

ArrayList<String> bres = new ArrayList<>();

bres.add(" ");

return bres;

}

char ch = str.charAt(0); // a

String ros = str.substring(1); //bc

ArrayList<String> rres = getSubSequence(ros); //[--,-c,b-,bc]

ArrayList<String> mres = new ArrayList<>();

for(String rstr: rres) {

mres.add(""+rstr);

}

for(String rstr : rres) {

mres.add(ch+rstr);

}

return mres;

}

}