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.Arrays;
import java.util.Scanner;
import java.util.stream.IntStream;

public class Main{
	static final Scanner s=new Scanner(System.in);
	static int getInt(){
		return Integer.parseInt(s.next());
	}
	static IntStream REPS(int l) {
		return IntStream.range(0,l);
	}
	public static void main(String[]__){
		int[]m=new int[26];
		for(char c:s.next().toCharArray())
			m[c-'a']++;
		System.out.println(
				Arrays.stream(m).anyMatch(i->i>1)
				?"no":"yes"
				);
	}
}