old_contents: from app import app
  from flask import render_template
  
  @app.route("/")
  def index():
      return render_template('index.html')
  
  if __name__ == "__main__":
      app.run()
new_contents: from app import app
  from flask import render_template
  
  
  @app.route("/")
  def index():
      return render_template('index.html')
subject: remove run