Read this and answer the question. If the question is unanswerable, say "unanswerable".

The Assembly consisted of nine seats, with electors casting nine equal votes, of which no more than two could be given to any individual candidate. It is a method of voting called a "weighted first past the post system". Four of the members of the Assembly formed the Executive Council, which devised policy and acted as an advisory body to the Administrator. The last Chief Minister of Norfolk Island was Lisle Snell. Other ministers included: Minister for Tourism, Industry and Development; Minister for Finance; Minister for Cultural Heritage and Community Services; and Minister for Environment.

Who was the only Chief Minister of Norfolk Island?
unanswerable