Point.cs

using System;

class Point
{
    public Point(int x, int y)
    {
        this.X = x;
        this.Y = y;
    }

    private int x;
    private int y;

    public int X {
        get
        {
            return this.x;
        }
        set
        {
            if ((x < 0) || (x > 100))
            {
                throw new ArgumentOutOfRangeException("Invalid value X. Must be between [0..100]!");
            }
            this.x = value;
        }
    }

    public int Y {
        get
        {
            return this.y;
        }
        set
        {
            if ((y < 0) || (y > 100))
            {
                throw new ArgumentOutOfRangeException("Invalid value Y. Must be between [0..100]!");
            }
            this.y = value;
        }
    }
}

class Program
{
    static void Main()
    {
        Point p1 = new Point(-300, -5);
        Console.WriteLine(p1.X);
        //Point p2 = new Point(0, 0);
    }
}