Find Elements That Have Maximal Sum

//  Write a program that reads two integer numbers N and K
//  and an array of N elements from the console. Find in the
//  array those K elements that have maximal sum.

using System;

class FindElementsThatHaveMaximalSum
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        int k = int.Parse(Console.ReadLine());
        int[] array = new int[n];
        int sum = 0;

        if (k > n)
        {
            Console.WriteLine("N must be bigger than K!");
            return;
        }

        for (int index = 0; index < n; index++)
        {
            array[index] = int.Parse(Console.ReadLine());
        }

        Array.Sort(array);

        for (int index = n - 1; index >= n - k; index--)
        {
            sum += array[index];
        }

        Console.WriteLine(sum);
    }
}