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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.*;
class Main {
 
	//最大公約数・最小公倍数（セットで使う）
static int gcd (int a, int b) {return b>0?gcd(b,a%b):a;}
static int lcm (int a, int b) {return a*b/gcd(a,b);}
   //整数かどうかを判定する
 static boolean isInteger(double number){return Math.ceil(number) == Math.floor(number); }

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		String[] input = sc.next().split("");
		Map<String,Boolean> map = new HashMap<>();

		for(String element : input){
				if(map.get(element) != null){
					System.out.println("no");
					return;
				}
		} 
		System.out.println("yes");
	}
}