Enter a string determines the character set included in the string.

• Title
  enter a string determines the character set included in the string.

• Input Description
  each data input a string with a maximum length of 100, and only contains the characters, it can not be the empty string, case sensitive.

• Description output
  of each data line, according to the character string of the original order, the output set of characters, i.e. letters after repeated and by not output.

• Examples

  输入
  abcqwerabc
  
  输出
  abcqwer
  

• Code

  import java.util.Scanner;
  
  class Solution {
      public static void main(String [] args) {
          Scanner in = new Scanner(System.in);
          String s1 = in.nextLine();
          if (s1 == null || s1.length() > 100) {
              return;
          }
          for (int i = 0; i < s1.length(); i++) {
              for (int j = i+1; j < s1.length(); j++) {
                  if (s1.charAt(i) == s1.charAt(j)) {
                      s1 = s1.substring(0,j)+s1.substring(j+1,s1.length());
                  }
              }
          }
          System.out.println(s1);
      }
  }
  

• operation result

  abcqwerabc
  abcqwer