Implement Existing Interface In C#

using System;
class Point: ICloneable // implementing IClonable Interface
    {
        public int x, y;
        public Point(int x, int y) {
            this.x = x;
            this.y = y;
        }
        public object Clone() {
            return new Point(this.x, this.y);
        }
        public override string ToString() {
            return ("X= " + x.ToString() + " Y= " + y.ToString());
        }
    }
class Porgram {
    static void Main(string[] args) {
        Point p1 = new Point(10, 10);
        Point p2 = (Point) p1.Clone();
        p2.x = 20;
        Console.WriteLine(p1);
        Console.WriteLine(p2);
        Console.ReadKey();
    }
}