Fill the grid with the numbers 1 through 9. In rows, columns and 3x3-boxes no number can be repeated. Additionaly place areas of the size 3x3 in the grid. It is not allowed that these areas overlap. Each of these areas contains at least one star. In the middle cell of such area can't be a star. Moreover each star is part of exactly one of these areas. In these areas also no number can be repeated.