Logic Masters Deutschland e.V.

Rules:
Place the digits from 1 to 6 inside the boldly outlined area in every row and column. Each digit represents a skyscraper with a hight that corresponds with the digit. Digits outside the outlined area represent the number of skyscrapers that is visible from that vintage point. Higher skyscrapers hide lower skyscrapers. The small numbers in the upper left corner of the dotted outlined areas are the sum of the digits inside that areas. Within areas, digits may not repeat.