using System;

using System.Linq;

using System.Collections.Generic;

using System.Linq.Expressions;

public class Program

{

    public static void Main()   

    {

        BinaryExpression add1 = Expression.MakeBinary(ExpressionType.Add, Expression.Constant(10.00), Expression.Constant(20.00));

        BinaryExpression add2 = Expression.MakeBinary(ExpressionType.Add, Expression.Constant(10.0), Expression.Constant(10.0));

        BinaryExpression subtract = Expression.MakeBinary(ExpressionType.Subtract, add1, add2);

        double result = Expression.Lambda<Func<double>>(subtract).Compile()();

        Console.WriteLine(result);

    }

}