Fillomino

Fillomino is a Japanese logic puzzle. The grid must be divided into areas of various sizes, as indicated by the given numbers.

Rules: A number must be entered in each cell of the grid so that areas of cells with the same number are created that are the same size as the number indicates.
Two different areas of the same size must not be orthogonally (but diagonally) adjacent.
Two default numbers may belong to the same area; there may also be areas that do not contain a single default number.