Introduces the concepts that echidnas can walk over spikes without getting killed 3 11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 1 1 1 1 1 1 1 1 1 0 0 0 0 1 0 1 0 1 0 0 2 2 2 2 2 2 2 1 1 0 0 0 0 1 0 1 1 1 0 0 2 2 2 2 2 2 2 1 1 0 0 0 0 1 0 0 0 0 0 0 3 1 1 1 1 1 1 1 1 0 0 0 1 1 1 0 0 0 0 0 2 2 2 2 2 2 2 1 1 0 0 0 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 1 1 0 0 0 1 1 1 0 0 0 0 0 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 18 9 3