User Registration Validation with Exceptions

# Introduction

In this challenge, we will simulate a registration system where users are required to input their name, age, and gender. The program will validate the inputs and prompt the user to re-enter if any of the inputs are invalid. We will be focusing on catching and handling exceptions, using exception objects and common exceptions, and using the `throw` and `throws` keywords. Additionally, we will create custom exception classes to handle specific validation scenarios.