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 scan = new Scanner(System.in);
    String[] s = scan.nextLine().split("");
    Map<String,Integer> map = new HashMap<>();
    
    int flg = 0;
    for(int i = 0;i<s.length;i++){
      if(map.get(s[i]) != null){
        flg++;
        System.out.println("no");
        break;
      }else{
        map.put(s[i],1);
      }
    }
    if(flg == 0){
      System.out.println("yes");
    }
        
  }
}