Draw a closed loop along the dotted lines that uses each grid point at most once. The numbers outside the grid indicate the sum of the numbers directly behind edges that are part of the loop in the respective row or column.
(Rules and example from WPC 2019 IB)
History of the puzzle
Appeared on WPC 2019/Round 12, an "innovations" round. The puzzles were written by Silke Berendes (Germany).
Appearances in the past WPCs
- WPC 2019/Round 12 by Silke Berendes