EXAM — the four-cell route
Trace EXAM through 1 at row 3, column 2; 2 at row 3, column 1; 3 at row 2, column 1; 4 at row 1, column 1. The cells read E → X → A → M, beginning within the fully open third row and finishing at the end of the first column.
From row 3, column 2, move left to row 3, column 1, then go up to row 2, column 1 and up again to row 1, column 1. The route contains one turn and two straight segments. It spans three rows and two columns, visits an edge three times, reaches one corner, and leaves 20 open cells for the remaining entries.