Summon

Rules

Enter given set of digits into the grid, so that each digit appears exactly once in each region. Cells with equal digits cannot touch each other, not even diagonally. Digits in adjacent cells within a row or column form multi-digit numbers, read from left to right or from top to bottom; digits without neighbours form single-digit numbers. The numbers outside the grid indicate the sum of all such multi-digit and single-digit numbers in the respective row or column.

(Rules (modified) and example (1-3) from WPC 2019 IB)

History of the puzzle

Invented by Serkan Yürekli (Turkey) in 2013. His first puzzle can be seen here.

Appearances in the past WPCs

• WPC 2019/World Cup Round 2 by Jürgen Blume-Nienhaus
• WPC 2017/Round 16 by Rajesh Kumar
• WPC 2017/Round 22 by Rajesh Kumar