#include <iostream> 

#include <fstream>  

using namespace std;



string monthName(int month)

{

    switch (month)

    {

    case 1:

        return "January";

    case 2:

        return "February";

    case 3:

        return "March";

    case 4:

        return "April";

    case 5:

        return "May";

    case 6:

        return "June";

    case 7:

        return "July";

    case 8:

        return "August";

    case 9:

        return "Spetember";

    case 10:

        return "October";

    case 11:

        return "November";

    case 12:

        return "December";

    }

    return "Nan";

}


int main()

{

    

    cout << "Enter your date of birth (YYYYMMDD) => ";

    string dob;

    cin >> dob;

    

    if (dob.length() != 8)

    {

        cout << "Invalid DOB";

        exit(0);

    }

    

    int flag = 1;

    for (int i = 0; i < dob.length(); i++)

    {

        if (dob[i] < 48 || dob[i] > 57)

        {

            flag = 0;

            break;

        }

    }

    if (flag == 0)

    {

        cout << "Invalid dob , must have only digits";

        exit(0);

    }

    

    int year = stoi(dob.substr(0, 4));

    int month = stoi(dob.substr(4, 2));

    int day = stoi(dob.substr(6, 2));

    

    if (month < 1 || month > 12)

    {

        cout << "Invalid Month";

        exit(0);

    }

    

    int age = 2020 - year;

    ofstream ofile(dob + ".txt"); 

    

    ofile << "You were born on " << day << " " << monthName(month) << " " << year << "\n";

    ofile << "Now, you are " << age << " years old.";

    

    ofile.close();

}