using NCalc;

using System;

​

public class Program

{

    public static void Main(string[] args)

    {

        Expression myExpr = new Expression("Math.Min(Math.Max((Math.Floor((180 * (0.6658 - 0.6658) + 450)/ 10) * 10), 300), 900)");

        System.Console.WriteLine(myExpr.Evaluate());

    }

}