First answer: DRY
Trace DRY through these cells: 1 at row 3, column 4; 2 at row 3, column 5; 3 at row 2, column 5. Reading them in sequence gives D → R → Y. The route begins with a move to the right and then turns upward, so both changes in position stay between orthogonally adjacent cells. That single turn converts a horizontal opening into a vertical finish.
This three-cell path has one turn and two straight segments. It spans two rows and two columns, visits an edge twice, and never enters a corner. The starting cell has three open orthogonal neighbors, while the ending cell has two. Those neighbor totals describe the untouched board rather than restrictions imposed by the route. Completing DRY assigns the first three cells and leaves 15 open cells for the other entries.