using System;

/*An array A consists of N integers.

The array contains an odd number of elements, and each element of the array can be paired 

with another element that has the same value, except for one element that is left unpaired.

For example, in array A such that:

​

  A[0] = 9  A[1] = 3  A[2] = 9

  A[3] = 3  A[4] = 9  A[5] = 7

  A[6] = 9

the elements at indexes 0 and 2 have value 9,

the elements at indexes 1 and 3 have value 3,

the elements at indexes 4 and 6 have value 9,

the element at index 5 has value 7 and is unpaired.

Find unpaired element

*/

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}