First Unique Character

Lab Java Intermediate 20 points

Read a word and print the first character that appears only once, or none. Use a LinkedHashMap<Character, Integer>.

Input

One word.

Output

A character or none.

Example

Input

swiss

Output

Sample input available Sample output available

Editor

Java

Hints

Count all characters first, then scan in insertion order.

Solution explanation

LinkedHashMap combines fast lookups with predictable order.

Show solution

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String w = sc.next();
        Map<Character, Integer> counts = new LinkedHashMap<Character, Integer>();
        for (char c : w.toCharArray()) {
            counts.put(c, counts.getOrDefault(c, 0) + 1);
        }
        String answer = "none";
        for (Map.Entry<Character, Integer> e : counts.entrySet()) {
            if (e.getValue() == 1) {
                answer = String.valueOf(e.getKey());
                break;
            }
        }
        System.out.println(answer);
    }
}

Output

Answer