Problem:
Score : 200 points

Problem Statement

You are given a string S consisting of lowercase English letters. Determine whether all the characters in S are different.

Constraints

2 ≤ |S| ≤ 26, where |S| denotes the length of S.

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If all the characters in S are different, print yes (case-sensitive); otherwise, print no.

Sample Input 1

uncopyrightable

Sample Output 1

yes

Sample Input 2

different

Sample Output 2

no

Sample Input 3

no

Sample Output 3

yes

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
  String s = sc.next();
  char[] c = s.toCharArray();
  String[] t = new String[s.length()];
  for(int i = 0;i < s.length();i++){t[i] = String.valueOf(c[i]);}
  HashSet<String> hs = new HashSet<String>();
  for(int i = 0;i < s.length();i++){hs.add(t[i]);}
  if(hs.size()==t.length)System.out.println("yes");
  else System.out.println("no");
}}