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using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            string shit = "19.5*x + (-15)";
            Console.WriteLine(Parser(shit));
        }

        public static bool IsZero(double number)
        {
            return System.Math.Abs(number) <= 10e-6;
        }
        public static string SolvePolynom(double first, double second, double third)
        {
            if (IsZero(first))
            {
                if (IsZero(second))
                {
                    if (IsZero(third))
                        return "1";
                    return "no roots";
                }
                else
                {
                    return (-third) / second + "";
                }
            }
            else
            {
                var discriminant = second * second - 4 * first * third;
                if (discriminant < 0)
                {
                    return "no roots";
                }
                else
                {
                    return (System.Math.Sqrt(discriminant) - second) / (2 * first) + "";
                }
            }
        }
        static string Parser(string text)
        {
            var coefs = new double[3];
            var shit = text.Split('+');

            foreach (var s in shit)
            {
                var power = 2;
                var number = new StringBuilder();
                for (int i = 0; i < s.Length; i++)
                {
                    if (char.IsLetter(s[i]))
                    {
                        if (i == s.Length || s[i + 1] != '^')
                            power = 1;
                        else power = 0;
                        break;
                    }

                    if (char.IsDigit(s[i]) || s[i] == '.' || s[i] == '-')
                    {
                        number.Append(s[i]);
                    }
                }
                var numberStr = number.ToString();

                if (string.IsNullOrEmpty(numberStr)) coefs[power] = 1;
                else if (numberStr == "-") coefs[power] = -1;
                else coefs[power] = double.Parse(numberStr, System.Globalization.CultureInfo.InvariantCulture);
            }
            return SolvePolynom(coefs[0], coefs[1], coefs[2]);
        }
    }
}