скобки

using System;
namespace Lectures
{
    class Program
    {
        static void Main()
        {
            string staples = "((())()())()";
            int numberOfOpenBrackets = 0;
            int numberOfCloseBrackets = 0;
            int counter = 0;
            int maximumInvestment = 0;
            bool mistake = false;

            foreach (var symbol in staples)
            {
                switch (symbol)
                {
                    case '(':
                        numberOfOpenBrackets++;
                        counter++;

                        if(counter > maximumInvestment)
                        {
                            maximumInvestment = counter;
                        }
                        break;
                    case ')':
                        numberOfCloseBrackets++;

                        if(counter > 0)
                        {
                            counter--;
                        }

                        else
                        {
                            mistake = true;
                        }
                        break;
                }
            }

            if (numberOfOpenBrackets == numberOfCloseBrackets && !mistake)
            {
                Console.WriteLine($"Строка корректна, максимальная глубина равна {maximumInvestment}.");
            }
            else
            {
                Console.WriteLine("Некорректная строка.");
            }
        }
    }
}