input: Write a function that creates a web application in Python using Flask that will take user input and generate an HTML page with the input. The function should return the Flask app instance.
  
  def create_web_app():
      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')
      
      return app
  
  assert create_web_app()
  assert create_web_app()
output: def create_web_app():
      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')
      
      return app