Logic Masters Deutschland e.V.

• Normal sudoku rules apply.
• Draw the world's longest slow thermo between the given bulb and tip.
  (In other words, draw a line from the large circle to the small circle such that each digit along the line is equal to or greater than the previous one)
• The length of the thermo is the theoretical maximum.
• The thermo may cross itself diagonally.

Play on F-Puzzles
Play on Sudokupad

Note: It's not too hard to solve the puzzle through trial-and-error, but there is a fully logical solution the whole way through!