def create_cfg_ti(run_dir, receptor_f, ligand_f, ambig_f, target_f):
    """
    Create HADDOCK3 configuration file for the first scenario.

    Parameters
    ----------
    run_dir : path or str
        Path to the run directory; where run results will be saved.

    receptor_f : Path or str
        Absolute path pointing to the receptor PDB file.

    ligand_f : Path or str
        Absolute path pointing to the ligand PDB file.

    ambig_f : Path or str
        Absolute path pointing to the `ambig.tbl` file.

    Return
    ------
    str
        The HADDOCK3 configuration file for benchmarking.
    """
    cfg_str = \
f"""
run_dir = {str(run_dir)!r}
ncores = 48

molecules = [
    {str(receptor_f)!r},
    {str(ligand_f)!r}
    ]

[topoaa]

[rigidbody]
ambig_fname = {str(ambig_f)!r}
sampling = 1000
noecv = false

[caprieval]
reference = {str(target_f)!r}

[seletop]
select = 200

[flexref]
ambig_fname = {str(ambig_f)!r}
noecv = true

[caprieval]
reference = {str(target_f)!r}

[mdref]
ambig_fname = {str(ambig_f)!r}
noecv = true

[caprieval]
reference = {str(target_f)!r}
"""
    return cfg_str