03.00 Instruction Set

using System;
class InstructionSet_broken
{
    static void Main()
    {
        while (true)
        {
            long result = 0;
            string opCode = Console.ReadLine().ToLower();
            if (opCode == "end") { break; }
            string[] codeArgs = opCode.Split(' ');
            switch (codeArgs[0])
            {
                case "inc":
                    {
                        long operandOne = long.Parse(codeArgs[1]);
                        result = operandOne + 1;
                        break;
                    }
                case "dec":
                    {
                        long operandOne = long.Parse(codeArgs[1]);
                        result = operandOne - 1;
                        break;
                    }
                case "add":
                    {
                        long operandOne = long.Parse(codeArgs[1]);
                        long operandTwo = long.Parse(codeArgs[2]);
                        result = operandOne + operandTwo;
                        break;
                    }
                case "mla":
                    {
                        long operandOne = long.Parse(codeArgs[1]);
                        long operandTwo = long.Parse(codeArgs[2]);
                        result = operandOne * operandTwo;
                        break;
                    }
              }
            Console.WriteLine(result);
        }

    }
}