14. On a rectangular chessboard filled with chess pieces, two players, A and B, take turns to pick up the pieces, following these rules: in a certain row or column, take any continuously placed pieces (i.e., cannot pick across empty spaces), not allowed to skip a turn, and cannot pick from multiple rows (or columns) at once. The game ends when all pieces on the chessboard are taken, and the player who takes the last piece wins.
Faced with the chessboard shown in the figure below, the first player has a winning strategy. The first move of the first player should be to take $\qquad$ (write down all correct solutions) to ensure victory.
Solution: After trying, it can only start with number 4; in other cases, there's no guarantee of winning.