LITS: one piece in every area

A Japanese logic puzzle with the Tetris pieces: every area hides an L, an I, a T or an S, and you have to find them all.

• Shade exactly four connected cells in every area: they must make an L, an I, a T or an S (turned or flipped is fine).
• All shaded cells must join up, with no shaded 2×2 block anywhere.
• Two equal pieces in different areas can’t share a side. Tap a cell to shade it, again to mark it empty, and drag to do many at once.

CA ES