Array

import java.util.Scanner;

public class SingleNumber {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter list of numbers:");
        String numString = scanner.nextLine();
        String[] numStringArray = numString.split(" ");
        int[] numArray = new int[numStringArray.length];
        for (int i = 0 ; i < numStringArray.length ; i++) {
            numArray[i] = Integer.parseInt(numStringArray[i]);
        }

        for (int j = 0 ; j < numArray.length ; j++){
            int counter = 0;
            for (int n = 0 ; n < numArray.length ; n++) {
                if (numArray[j] == numArray[n]) {
                    counter++;
                }

            }
            if (counter == 1) {
                System.out.println(numArray[j]);
                break;
            }
        }

       scanner.close();
    }

}