using System;

​

public class Student

{

    public string clas;

    public string id;

    public string name;

    private double dBEL, dForeign, dMath, dPhys, dChem, dBio;

    private double average;

    public double DBEL

    {

        set { if (value >= 2.00 && value <= 6.00) this.dBEL = value; } 

        get { return this.dBEL; } 

    }

    public double DForeign

    {

        set { this.dForeign = value; }

        get { return this.dForeign; }

    }

    public double DMath

    {

        set { this.dMath = value; } 

        get { return this.dMath; }

    }

​

    public double DPhys

    {

        set { this.dPhys = value; } 

        get { return this.dPhys; }

    }

    public double DChem

    {

        set { this.dChem = value; } 

        get { return this.dChem; }

    }

    public double DBio

    {

    }

}

​

public class Program

{

    public static void Main()

    {

    }

}

​