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 C# (.NET Core 3.1.201) (judge verdict: Wrong Answer)

using System;
using System.Linq;

namespace Sample
{
  class Sample
  {
    static void Main(string[] args)
    {
      
      string S=Console.ReadLine();
      string[] arr=new string[S.Length];
      
      for(int i=0;i<S.Length-1;i++){
        arr[i]=S.Substring(i,1);
      }
    string[] dis=arr.Distinct().ToArray();
      if(dis.Length!=arr.Length){
        Console.WriteLine("no");
      }else{
        Console.WriteLine("yes");
      }
    }
    
  }

}