<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def from_structure(cls, structure, ff_elements=None, atom_style="charge"):
 """ Simple constructor building LammpsData from a structure without force field parameters and topologies. Args: structure (Structure):
 Input structure. ff_elements ([str]):
 List of strings of elements that must be present due to force field settings but not necessarily in the structure. Default to None. atom_style (str):
 Choose between "atomic" (neutral) and "charge" (charged). Default to "charge". """

        s = structure.get_sorted_structure()
        box, symmop = lattice_2_lmpbox(s.lattice)
        coords = symmop.operate_multi(s.cart_coords)
        site_properties = s.site_properties
        if "velocities" in site_properties:
            velos = np.array(s.site_properties["velocities"])
            rot = SymmOp.from_rotation_and_translation(symmop.rotation_matrix)
            rot_velos = rot.operate_multi(velos)
            site_properties.update({"velocities": rot_velos})
        boxed_s = Structure(box.to_lattice(), s.species, coords,
                            site_properties=site_properties,
                            coords_are_cartesian=True)

        symbols = list(s.symbol_set)
        if ff_elements:
            symbols.extend(ff_elements)
        elements = sorted(Element(el) for el in set(symbols))
        mass_info = [tuple([i.symbol] * 2) for i in elements]
        ff = ForceField(mass_info)
        topo = Topology(boxed_s)
        return cls.from_ff_and_topologies(box=box, ff=ff, topologies=[topo],
                                          atom_style=atom_style)