static void Main(string[] args) { //C1 c1 = new C1(); //string r = c1.Data(5, "ALi"); //WriteLine(r); //............ //C1 c1 = new C1(); //WriteLine(c1.Data(4, "Bilal")); //...... IF1 f1 = new C1(); WriteLine(f1.Data(5, "Bilal")); IF2 f2 = new C1(); WriteLine(f2.Data(10, "Khalil")); ReadKey(); }