Lost Sums/en

Instructions

    

Fill the grid with digits from 1 to 9. Numbers inside a shaded cell indicate the sums of all white cell blocks that can be seen from that cell, in four main directions (up, down, left, right). No digit may be repeated within a single block. Cell blocks are visible until they meet another shaded cell or the edge of the grid. Given sums do not indicate any direction.

History

This puzzle type was used in WPC 2010 Poland.