memorable special shapes

When solving special shapes, I have encountered the same patterns. This special shape has been remembered for its special diagonal. One has a diagonal of four, the other of two. When I received similar sudokus, I became skeptical and I will not solve the same sudokus. Difficult special shape 17.01.14 [IMG]http://imagizer.imageshack.us/v2/xq90/691/py5o.png[/IMG] Difficult special shape 31.01.14 [IMG]http://imagizer.imageshack.us/v2/xq90/198/cjg6.jpg[/IMG]