Jigsaw Sudoku

1. 1Fill the grid so that every row, every column and every piece holds the digits 1 to 9 exactly once.
2. 2The thick lines draw nine irregular pieces of nine squares each. They replace the 3 by 3 boxes of a classic sudoku: everything else works the same.
3. 3Look where a piece reaches into a row or a column: a digit that must sit in that part of the piece cannot appear anywhere else in that line. Selecting a square lights up its row, its column and its piece.
4. 4Check my work marks the digits that are wrong. A hint fills in one square: it costs a little XP, never time.
5. 5There is a new puzzle every day, the same for everyone: easy on Monday and Tuesday, medium on most days, hard on Saturday. Every puzzle has one solution and can be solved by logic alone.

Keyboard: arrows to move, 1 to 9 to write, N for notes, Backspace to erase, U to undo.