ƒ RULEZZLE

TODAY'S RULEZZLE

Find the input.
Crack the function.

The rule is hidden. Use the outputs to work out which input reaches today’s target.

TARGET OUTPUT —
Enter a whole number up to five digits

Loading today’s puzzle…

HOW TO PLAY

Find today’s hidden rule.

  1. Enter a whole number using up to five digits. Missing places are filled with leading zeroes.
  2. Study the output produced by the secret function.
  3. Reach the target output in ten guesses or fewer.

The function changes every day. It might use maths, digit patterns, or something less obvious.