using System;

public class Program

{

    public static void Main()

    {

        int D, M, Y;

        Console.WriteLine("enter day");

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

        Console.WriteLine("enter month");

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

        Console.WriteLine("enter year");

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

        if((M == 4 || M == 6 || M == 9 || M == 11 || M == 2 || M == 8) && D == 1)

        {

            D = 31;

            M = M - 1;

        }

        else if ((M == 12 || M == 5 || M == 7|| M == 10) && D == 1)

        {

            D = 30;

            M = M - 1;

        }

        else if (M == 3)

            if (Y % 4 == 0 && D == 1)

            {

                D = 29;

                M = M - 1;

            }

            else if (Y % 4 != 0 && D == 1)

            {

                D = 28;

                M = M - 1;

            }

            else 

                D = D - 1;

        else if (M == 1 && D == 1)

        {

            D = 31;

            M = 12;

            Y = Y - 1;

        }

        else

            D = D - 1;

        Console.WriteLine("the date befor is {0}.{1}.{2}", D, M, Y);

    }

}