Nonogram

1. Each row and each column has a clue: a list of numbers on its left or on top.
2. Each number is a run of filled squares in that line, in the same order. The clue 3 1 means a run of 3, at least one empty square, then a run of 1.
3. Fill the squares that the clues need, and cross out the squares that must stay empty.
4. When every row and every column matches its clue, the picture is complete.

Tap or click a square to fill it. Drag along a row or a column to fill many squares at once. Switch to Cross to mark empty squares on a phone, or right click with a mouse. On a keyboard, move with the arrow keys, press Space to mark, X to cross out, and Z to undo. A clue turns grey when its line matches it.

• Start with the big numbers. A run of 8 in a line of 10 must cover the middle 6 squares, wherever it starts.
• Add up a clue: the runs plus one empty square between each two. When the total is the length of the line, the whole line is known.
• A clue of 0 means the whole line is empty. Cross it out at once.
• Use the edges. A filled square at the edge of the grid starts the first run of its line.
• Cross out squares that no run can reach. Each cross gives the other lines more to work with.
• Go back and forth between rows and columns. Each new square in a row is a new clue for its column.

Every puzzle here has one answer, and you never need to guess. Before a puzzle reaches you, a solver checks that line-by-line logic alone fills every square. Stuck? Press Hint: it shows a wrong square first, or else the next square that one row or column gives.