Logic Masters Deutschland e.V.

Normal sudoku rules apply.

If and only if adjacent digits sum to an even number, shade the boundary between them. Shaded boundaries divide the grid into regions. Digits may repeat within a region.

Numbers in circle indicate the size of the region. Not all regions have a circle, some regions have many. All possible circles are given.

Play online (SudokuPad)

Alice and the Bat-Winged Ballet

One fine afternoon, when the clouds were shaped like teapots and the breeze smelled faintly of marmalade, Alice wandered into a meadow that had no business being so upside-down. The grass grew from the sky, and the daisies wore spectacles to read the sun.

“Oh dear,” said Alice, adjusting her ribbon, “this must be the place where logic comes to nap.”

Just then, a flurry of flapping erupted above her head. She looked up and gasped—not one, not two, but a whole parliament of butterflies were dueling mid-air! Their wings were not the soft, fluttery kind one might expect, but leathery and bat-like, flapping with the indignation of a misunderstood poem.

They twirled and tumbled, pirouetting like prima ballerinas in a quarrel over who had the better tutu. One butterfly, with stripes like peppermint and a monocle glued to its antenna, shouted, “En garde!” and swooped at another who wore a tiny top hat and wielded a toothpick like a rapier.

Alice clapped her hands in delight. “Oh, how wonderfully absurd! Are they fighting or dancing?”

A nearby mushroom, who had been watching the spectacle with a bored expression, replied, “Both. It’s the Annual Aerial Argument. They argue in choreography. Very fashionable among the winged elite.”

“But what are they arguing about?” asked Alice.

“Whether marmalade is superior to jam,” said the mushroom. “It’s a sticky subject.”

Just then, the butterflies formed a perfect spiral and descended like a corkscrew into a puddle that promptly turned into a mirror. They vanished with a splash and a giggle.

Alice blinked. “I do hope they settled it.”

“Oh, they never do,” said the mushroom. “But they always look splendid trying.”

And with that, Alice skipped off, humming a tune that sounded suspiciously like a contradiction.