import os
from flask import Flask

app = Flask(__name__)

@app.route('/')
def index():
  return """
    <h1>Hello World!</h1>
    <a href="/about">Sobre</a>
    <br>
    <a href="/contact">Contato</a>
  """

@app.route('/about')
def about():
  return 'Sobre mim'

@app.route('/contact')
def contact():
  return 'Contato'

if __name__ == '__main__':
  port = int(
    os.environ.get('PORT', 5000)
  )
  app.run(
    host='0.0.0.0',
    port=port
  )
