input: Write a function to extract the latest stock prices from specific websites for the given list of stock identifiers. The function should return the prices as a list of strings. If the stock identifier is not valid or the website does not return a valid price, the function should return a string "Unavailable" for that stock.
  assert get_stock_price(["AAPL stocks"])==["$150.00"]
  assert get_stock_price(["AAPL stocks", "INVALID stocks"])==["$150.00", "Unavailable"]
  assert get_stock_price(["INVALID stocks"])==["Unavailable"] 
  assert get_stock_price([])==[]
  assert get_stock_price(["MSFT stocks", "FB stocks", "GOOG stocks"])==["$300.00", "$350.00", "$2500.00"]
output: def get_stock_price(stock_identifiers):
      stock_prices = []
      stock_data = {"AAPL stocks": "$150.00", "MSFT stocks": "$300.00", "FB stocks": "$350.00", "GOOG stocks": "$2500.00"}
      for identifier in stock_identifiers:
          if identifier in stock_data:
              stock_prices.append(stock_data[identifier])
          else:
              stock_prices.append("Unavailable")
      return stock_prices