You need a table first of all... it's not easy, it takes time but it's interesting... I solved it once with my brother, 2 heads are better than one.
Yep! I found on Google solution and it was just as I thought - more like matrix, rows and columns. It even requires to pay attention on written solution and no wonder how it wouldn't be for solving on your own hand with the paper.
These things are always very entertaining and interesting. But the end leads to - the German.
The answer wasn't hard at all for those who use their smell or instinct and hit the German immediately as an answer.