using System;

public class Program

{

    public static void Main()

    {

        Console.Write("enter an input");

        int hisnum = int.Parse(Console.ReadLine()) ;

        // لكي نضمن ان العدد المدخل مكون من 7 منازل

        if (!(hisnum >= 100000 && hisnum <= 999999))

        {

        Console.WriteLine("Error : Invalid number ");

            return;

        }

        //    العمليات الحسابية لتفكيك الرقم المدخل

        int hi = (hisnum / 10000) ;

        int um  = hisnum % 100 ;

        int sn = (hisnum / 100) %100 ;

        // لكي نضمن ان مدخلات الشهر صحيحية

    if (!(sn>=0 && sn <= 12))

        { Console.WriteLine("Error : Invalid mounth number ");

            return;

        }

        if (sn == 4 || sn == 6 || sn == 9 || sn == 11)

        { 

        if (hi >= 30)

        {

        Console.WriteLine("Error : Invalid mounth OR Day number");

            return;

        }

        }

        // شهر 2 والسنة الكبيسة 

        else if (sn == 2)

        {

            if ( um % 4 == 0 && !(hi <=29 )) 

            {

                    Console.WriteLine("Error : Invalid mounth OR Day number ") ;

                return;

                }

                else if (!(um % 4 == 0))

                {

                    if ( hi != 28)

                {

                    Console.WriteLine("Error : Invalid mounth OR Day number ") ;

                return;

                }

                }

            }

        // لكي نضمن ان مدخلات الأيام صحيحة

        if (hi > 31 )

        {

        Console.WriteLine("Error : Invalid Day number ") ;

            return;

            {

            }

        }

        //Operation 2 ...

        Console.Write(hi);

        if (sn == 1)

        {Console.Write(" January ");}

        if (sn == 2)

        {Console.Write(" February ");}

        if (sn == 3)

        {Console.Write(" March ");}

        if (sn == 4)

        {Console.Write(" April ");}

        if (sn == 5)

        {Console.Write(" May ");}

        if (sn == 6)

        {Console.Write(" June ");}

        if (sn == 7)

        {Console.Write(" July ");}

        if (sn == 8)

        {Console.Write(" August ");}

        if (sn == 9)

        {Console.Write(" September ");}

        if (sn == 10)

        {Console.Write(" October ");}

        if (sn == 11)

        {Console.Write(" November ");}

        if (sn == 12)

        {Console.Write(" December ");}

        Console.Write(1900 + um);

    }

}

​

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