package Others;

import java.io.BufferedReader;
import java.io.InputStreamReader;

/**
 * @author Varun Upadhyay (https://github.com/varunu28)
 */

public class RemoveDuplicateFromString {
 public static void main(String[] args) throws Exception {
 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 String inpStr = br.readLine();

 System.out.println("Actual string is: " + inpStr);
 System.out.println("String after removing duplicates: " + removeDuplicate(inpStr));

 br.close();
 }

 /**
 * This method produces a string after removing all the duplicate characters from input string and returns it
 * Example: Input String - "aabbbccccddddd"
 * Output String - "abcd"
 *
 * @param s String from which duplicate characters have to be removed
 * @return string with only unique characters
 */

 public static String removeDuplicate(String s) {
 if (s == null || s.isEmpty()) {
 return s;
 }

 StringBuilder sb = new StringBuilder();
 int n = s.length();

 for (int i = 0; i < n; i++) {
 if (sb.toString().indexOf(s.charAt(i)) == -1) {
 sb.append(String.valueOf(s.charAt(i)));
 }
 }

 return sb.toString();
 }
}