MathDB

On the "battleship" field (a square of

10\times 10

cells),

10

"ships" are placed in the following sequence: first one "ship" of size

1\times 4

, then two - of size

1\times 3

, three - of size

1\times 2

, and, finally, four -

1\times 1

. The rules do not allow "ships" to touch each other even with their tops. Can it happen that when part of the "ships" have already been displayed, there is nowhere to place the next one?

Problem Statement