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.Scanner;
public class Main {
    public static void main(String[] args) {
		try{
			Scanner sc = new Scanner(System.in);
			String input = sc.next();
			String result = "yes";
			first : for(int i = 0 ; i < input.length()-1 ; i++){
				for(int j = i+1; j < input.length(); j++){
					if(input.charAt(i) == input.charAt(j)){
						result = "no";
						break first;
					}
				}
			}
			System.out.println(result);
		}catch(Exception e){
			e.getMessage();
		}
	} 
}