K, the Key, is to be moved to contact L, the Latch, so as to move it totally into the grey area.

Locked K → L →

Open L

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1 3 2 8 9 10 K → 5 L → 4 6 11 7

The object again is to move K to dislodged L. The "tumblers", the numbered blocks, are only to slide in the direction of their respective lengths.

How might you accomplish this?

Note: the black areas are void space.