Facebook Hacker Cup 2013 Round 1 Card Game... but something is wrong

CardGame.java

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;

/**
 * @author psy
 * 
 */
public class CardGame {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		List<String> output = new LinkedList<String>();

		CardGame game = new CardGame();

		int games = Integer.parseInt(in.nextLine());

		for (int i = 1; i <= games; i++) {
			String nkString = in.nextLine();
			String cardString = in.nextLine();

			String[] nkArray = nkString.split(" ");
			String[] cardArray = cardString.split(" ");

			List<Integer> cards = new ArrayList<Integer>();
			for (String card : cardArray) {
				cards.add(Integer.parseInt(card));
			}

			int result = game.findMaxSum(Integer.parseInt(nkArray[0]), Integer.parseInt(nkArray[1]), cards);

			output.add("Case #" + i + ": " + result);
		}

		for (String out : output) {
			System.out.println(out);
		}
	}

	public int findMaxSum(int n, int k, List<Integer> cards) {

		Collections.sort(cards, new Comparator<Integer>() {

			public int compare(Integer o1, Integer o2) {
				// big first
				return o2.compareTo(o1);
			}
		});

		long result = 0;
		int cardCounter = 0;

		for (Integer value : cards) {
			cardCounter++;

			if (n - cardCounter < k - 1) {
				break;
			}

			long cardPossCounter = binomCoef(n - cardCounter, k - 1);

			result += value * cardPossCounter;
		}

		return (int) (result % 1000000007L);
	}

	private long binomCoef(int n, int k) {
		if (k > n) {
			throw new IllegalArgumentException("k cannot be greater than n");
		}

		long result = 1;

		for (int i = n - k + 1; i <= n; i++) {
			result = result * i;
		}

		for (int i = 1; i <= k; i++) {
			result = result / i;
		}
		return result;
	}
}

yep i know... fixing it later... maybe