<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def write_supercells_with_displacements(supercell, cells_with_disps, filename="geo.gen"):
 """Writes perfect supercell and supercells with displacements Args: supercell: perfect supercell cells_with_disps: supercells with displaced atoms filename: root-filename """


    # original cell
    write_dftbp(filename + "S", supercell)

    # displaced cells
    for ii in range(len(cells_with_disps)):
        write_dftbp(filename + "S-{:03d}".format(ii+1), cells_with_disps[ii])