using System;

public class Program

{

    private const string args = "1200|20|12";

    public static void Main()

    {

        string[] parameters = args.Split('|');

        if (parameters.Length == 3 && float.TryParse(parameters[0], out float cdpVelocity) && float.TryParse(parameters[1], out float cdpWidth) && float.TryParse(parameters[2], out float cdpHeight))

        {

            double result = CalcDifferentialPressure(cdpVelocity, cdpWidth, cdpHeight);

            Console.WriteLine($"Parameters => {args}");

            Console.WriteLine($"Velocity => {cdpVelocity}");

            Console.WriteLine($"Width => {cdpWidth}");

            Console.WriteLine($"Height => {cdpHeight}");

            Console.WriteLine($"Result => {result}");

        }

        else

            Console.WriteLine($"Invalid parameters => {args}");

    }

    private static double CalcDifferentialPressure(float velocity, float width, float height)

    {

        double A = 0.3917;

        double B = -14.908;

        double Small_C = -0.3608;

        double Small_D = 35.343;

        double Small_E = 1510;

        double Big_C = -0.5601;

        double Big_D = 35.871;

        double Big_E = 1399;

        double F = -0.000002;

        double G = 0.0002;

        double J = -0.0045;

        double L = 0.5174;

​

        double C, D, E, K, M;

​

        if (width > 12)

        {

            C = Big_C;

            D = Big_D;

            E = Big_E;

        }

        else

        {

            C = Small_C;

            D = Small_D;

            E = Small_E;

        }

​

        K = A * Math.Pow(width, 2) + B * width + C * Math.Pow(height, 2) + D * height + E;

        M = F * Math.Pow(width, 3) + G * Math.Pow(width, 2) + J * width + L;

​

        return Math.Pow(velocity / K, 1 / M);

    }

}