Logic Masters Deutschland e.V.

Inspired by twototenth's excellent Region X-Sums - if you enjoy this slightly more approachable puzzle, check out that one!

Rules:

Regular sudoku rules apply in the central 9x9 cells.

X-sums: a number outside the grid gives the sum of the first X digits along the indicated row or column in the indicated direction, where X is the first of those digits.

Region sum lines: Along each blue line, the sum of the numbers in each region it passes through is always the same.

For the purpose of the region sum lines, the outside of the grid counts as one region. Every cell an equal sums line passes through must contain a number.

Play online:

F-puzzles

Sven's Web App (CtC)

Unfortunately solution check is unavailable. For marking double-digit numbers, I recommend using a corner mark for the tens and center mark for the ones. No, it's not ideal and I should probably learn how to use Penpa+.