7.14 There is a $5 \times 5$ square grid chessboard, consisting of 25 $1 \times 1$ unit square cells. At the center of each unit square cell, a red dot is painted. Please find several straight lines on the chessboard that do not pass through any red dots, dividing the chessboard into several pieces (which may be of different shapes and sizes), such that each piece contains at most one red dot. How many straight lines do you need to draw at a minimum? Provide an example of such a drawing and prove your conclusion.