Analyze the sentiment expressed in the tweet. Is it positive, negative, or neutral? Explain the sentiment in relation to the stock mentioned.
TWEET: "Hi @facebook why I can't use the username "sigitlegio" ? No one claim this username, but why the username not avail… https://t.co/imTFk9wo9u

" STOCK: Facebook DATE: 02/09/2018
Sentiment: (Provide sentiment here)
Explanation: The tweet sentiment is related to the stock mentioned, and it's important to interpret the context. The LSTM polarity score is 1 and the TextBlob polarity score is 0.0.