text: import logging
  import os
  
  from flask import Flask, redirect, render_template, request, url_for
  from flask_sslify import SSLify
  
  app = Flask(__name__)
  sslify = SSLify(app, permanent=True)
  
  
  # Page Routes
  @app.route('/')
  @app.route('/index')
  def index():
      return render_template('index.html')
  
  
  @app.route('/_ah/warmup')
  def warmup():
      # Handle your warmup logic here, e.g. set up a database connection pool
      return '', 200, {}
  
  
  # File Routes
  @app.route('/sitemap.xml')
  def sitemap():
      return app.send_static_file('sitemap.xml')
  
  
  @app.route('/robots.txt')
  def robots():
      return app.send_static_file('robots.txt')
  
  
  @app.route('/favicon.ico')
  def favicon():
      return app.send_static_file('favicon.ico')
  
  
  # Error Routes
  @app.errorhandler(404)
  def page_not_found(e):
      return render_template('404.html'), 404
  
  
  @app.errorhandler(500)
  def server_error(e):
      return render_template('500.html'), 500
  
  
  if __name__ == '__main__':
      # Bind to PORT if defined, otherwise default to 5000.
      port = int(os.environ.get('PORT', 5000))
      app.run(host='127.0.0.1', port=port)
  