Placing Rook

Fluffy the squirrel is playing chess today. He has a n times n chessboard. An integer is written on each square of the chessboard. A rook is a chess piece, which can attack every square in its row and column, including the square its standing on. Fluffy would like to place a rook on the chessboard. He defines the score of the rook as the sum of the integers written in all the squares it attacks.