input: Write a function to create a web application in Python using Flask that takes user input and generates an HTML page displaying the input. The function should define the Flask application, the routes, and the HTML templates.
  
  from flask import Flask, render_template, request
  
  app = Flask(__name__)
  
  @app.route('/', methods=['GET', 'POST'])
  def home():
      if request.method == 'POST':
          input_text = request.form.get('input_text')
          return render_template('result.html', input_text=input_text)
      return render_template('index.html')
  
  if __name__ == '__main__':
      app.run(debug=True)
  
  assert home('<form method="post"><input type="text" name="input_text"><input type="submit"></form>')=='''<html>
   <body>
    <h1>Your Input: </h1>
    <p>example input</p>
   </body>
  </html>'''
  assert home()=='''<html>
   <body>
    <h1>Welcome to Home Page</h1>
   </body>
  </html>'''
output: 
  @app.route('/', methods=['GET', 'POST'])
  def home():
      if request.method == 'POST':
          input_text = request.form.get('input_text')
          return render_template('result.html', input_text=input_text)
      return render_template('index.html')
  