input: Write a function to extract the latest stock prices from specific websites using web scraping techniques in Python. If the scraping is successful, return a string in the format "The price of {stock} is {price}.". If the stock is not found or the website cannot be scraped, return "Stock price not available." for that stock. The function should utilize the `requests` and `BeautifulSoup` libraries to perform the scraping.
  assert get_stock_price("AAPL stocks")=="The price of AAPL stocks is $XXX.XX."
  assert get_stock_price("MSFT stocks")=="The price of MSFT stocks is $XXX.XX."
  assert get_stock_price("FB stocks")=="The price of FB stocks is $XXX.XX."
  assert get_stock_price("GOOG stocks")=="The price of GOOG stocks is $XXX.XX."
  assert get_stock_price("INVALID stocks")=="Stock price not available."
output: def get_stock_price(stock):
      import requests
      from bs4 import BeautifulSoup
      url = f"https://example.com/stock/{stock.replace(' stocks', '')}"
      try:
          response = requests.get(url)
          response.raise_for_status()
          soup = BeautifulSoup(response.text, 'html.parser')
          price = soup.find('span', class_='price').text
          return f"The price of {stock} is {price}."
      except:
          return "Stock price not available."