1. SHRINK — six cells
Trace SHRINK from 1 at row 1, column 6; 2 at row 1, column 5; 3 at row 1, column 4; 4 at row 2, column 4; 5 at row 2, column 5; 6 at row 3, column 5. Reading those cells in sequence gives S → H → R → I → N → K, with every consecutive pair sharing an edge.
The movement is left, left, down, right, then down. That produces three turns and four straight segments across a span of three rows and three columns. The path visits an edge three times and a corner once. Both its starting and ending cells have two open orthogonal neighbors, which helps pin down the endpoints. Assigning these six cells leaves 24 open cells for the remaining three routes.