在8×8的国际象棋棋盘上，如果在某些位置放置若干个马之后，使整个棋盘中任意空位置上所放置的棋子均能被这些马吃掉，则把这组放置的棋子称为一个满覆盖。求解一个最小满覆盖-On 88 chess board, if placed after several horses at certain locations, so that the whole board to any empty position on the placed pieces can be eaten by the horses,