text: # let's import the flask
  from flask import Flask
  import os # importing operating system module
  
  app = Flask(__name__)
  
  @app.route('/') # this decorator create the home route
  def home ():
      return '<h1>Welcome</h1>'
  
  @app.route('/about')
  def about():
      return '<h1>About us</h1>'
  
  
  if __name__ == '__main__':
      # for deployment we use the environ
      # to make it work for both production and development
      port = int(os.environ.get("PORT", 5000))
      app.run(debug=True, host='0.0.0.0', port=port)
  