Locate the position of the 16 T-forms in the grid. The T-forms fill all cells and don't overlap. The forms can be rotated but not reflected. Every row, every column, every marked 4x2 box and both main diagonals contain the digits 1 through 8. The place of 3 T-forms is given.
Place the given pieces into the grid without overlapping them. Then fill in the grid so that every column, and every 3x3 box contains the digits 1 through 9.
The four corner boxes of the finalized grid have been marked with dots on the pieces too.
Fill the grid with the digits 1 to 9. Each row, column and 3x3-box has exactly one of each digit. The strips in the left and in the top mark the distance and order of the two digits of this strip in this row or column.