text: import unittest
  from selenium import webdriver
  from time import sleep
  
  class NavigationTest(unittest.TestCase):
  
      def setUp(self):
          self.driver = webdriver.Chrome(executable_path='/usr/bin/chromedriver')     
          driver = self.driver
          driver.implicitly_wait(30)
          driver.maximize_window()
          driver.get('https://the-internet.herokuapp.com/')
          driver.find_element_by_link_text('Add/Remove Elements').click()
  
  
      def test_add_remove(self):
          driver = self.driver
  
          elements_added = int(input('How many elements will you add?: '))
          elements_removed = int(input('How many elements will you removed?: '))
          total_elements = elements_added - elements_removed
  
          add_button = driver.find_element_by_xpath('/html/body/div[2]/div/div/button')
  
          sleep(3)
  
          for i in range(elements_added):
              add_button.click()
          
          for i in range(elements_removed):
              try:
                  delete_button = driver.find_elements_by_xpath('/html/body/div[2]/div/div/div/button[1]')
                  delete_button.click()
              except:
                  print('You\'re trying to delet more elements than exist')
                  break
          
          if total_elements > 0:
              print(f'there are {total_elements} elements on screen')
          
          else:
              print('There are 0 elements on the screen')
          
          sleep(3)
  
          
      def tearDown(self):
          self.driver.close()
  
  if __name__ == "__main__":
  	unittest.main(verbosity = 2)