sample

public class Program
{
    public static void Main()
    {
        bool isInvalidInput = false;
        bool isTie = false;

        do
        {
            Console.WriteLine("Jack Please enter 1 for Paper, 2 for Rock, 3 for Scissors:");
            string jackInput = Console.ReadLine();
            Console.WriteLine("Jill Please enter 1 for Paper, 2 for Rock, 3 for Scissors:");
            string jillInput = Console.ReadLine();

            if (IsInvalidInput(jackInput) || IsInvalidInput(jillInput))
            {
                Console.WriteLine("Invalid input detected, please insert 1, 2, or 3");
                isInvalidInput = true;
            }
            else
            {
                isInvalidInput = false;
                // convert input to numbers
                if (Jack == Jill)
                {
                    Console.WriteLine("Nobody wins");
                    isTie = true
                }
                else
                {
                    //el resto del juego
                }
            }
        }
        while (isTie || isInvalidInput);
    }

    private static bool IsInValidInput(string input)
    { //check if input is invalid
    }
}