Three in one (50/50)

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        string cards = Console.ReadLine();
        var card = cards.Split(',');
        var players = new List<int>();
        foreach (var item in card)
        {
            players.Add(int.Parse(item));
        }
        Console.WriteLine(CardsWinner(players));

        string cakes = Console.ReadLine();              // Task 2
        int friends = int.Parse(Console.ReadLine());
        Console.WriteLine(BitesOfCake(cakes,friends));

        string coins = Console.ReadLine();
        Console.WriteLine(CalcTransactions(coins));
    }
    private static int CardsWinner(List<int> points)
    {
        int bestPoints = -1;
        int bestPlayer = -1;

        for (int i = 0; i < points.Count; i++)
        {
            if (points[i] > 21)
            {
                continue;
            }
            if (points[i] > bestPoints)
            {
                bestPoints = points[i];
                bestPlayer = i;
            }
            else if (points[i] == bestPoints)
            {
                bestPlayer = -1;
            }
        }
        return bestPlayer;
    }

    private static int BitesOfCake(string cake, int friends)
    {
        string[] cakes = cake.Split(',');
        Array.Sort(cakes);
        int bites = 0;
        int lenght = cakes.Length;
        for (int i = lenght - 1; i >= 0; i -= friends + 1)
        {
            bites += int.Parse(cakes[i]);
        }
        return bites;
    }

    private static int CalcTransactions(string coin)
    {
        string[] coins = coin.Split(' ');
        int G1 = int.Parse(coins[0]);
        int S1 = int.Parse(coins[1]);
        int B1 = int.Parse(coins[2]);
        int G2 = int.Parse(coins[3]);
        int S2 = int.Parse(coins[4]);
        int B2 = int.Parse(coins[5]);

        int exchangeOperations = 0;
        while (G2 > G1)
        {
            --G2;
            S2 += 11;
            exchangeOperations++;
        }

        while (S2 > S1)
        {
            if (G1 > G2)
            {
                --G1;
                S1 += 9;
                exchangeOperations++;
            }
            else
            {
                --S2;
                B2 += 11;
                exchangeOperations++;
            }
        }

        while (B2 > B1)
        {
            if (S1 > S2)
            {
                --S1;
                B1 += 9;
                exchangeOperations++;
            }
            else if (G1 > G2)
            {
                --G1;
                S1 += 9;
                exchangeOperations++;
            }
            else
            {
                return -1;
            }
        }

        return exchangeOperations;
    }
}