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: Wrong Answer)

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		ArrayList<Integer> num = new ArrayList<Integer>();
		ArrayList<String> param = new ArrayList<String>();
		int system = 0; // 文字の空白区切り　0:ON　1:OFF

		while (sc.hasNext()) {
			if (sc.hasNextInt()) {
				num.add(sc.nextInt());
			} else {
				if(system==0) param.add(sc.next());
				if(system==1) param.add(sc.nextLine());
			}
		}
		Method(num, param);
	}

	static void Method(ArrayList<Integer> num, ArrayList<String> param) {
		boolean flag = false;
		String target = "";
		
		param = new ArrayList<String>(Arrays.asList(param.get(0).split("")));

		for(int i = 0; i < param.size(); i++){
			target = param.get(0);
			param.remove(0);
			if(param.contains(target)) flag = true;
		}
		
		if(!flag){
			System.out.println("yes");
		} else {
			System.out.println("no");
		}
	}
}