static boolean isWhitePiece(int i, int j) {
        if ((i < 0) || (j < 0)) {
            return true;
        }
        if ((i > 11) || (j > 11)) {
            return true;
        }
        return (board[i][j] == 'P')
                || (board[i][j] == 'T')
                || (board[i][j] == 'N')
                || (board[i][j] == 'C')
                || (board[i][j] == 'D')
                || (board[i][j] == 'R');
    }