  The elliptic azimuthal anisotropy coefficient ($v_2$) is measured for charm
(D$^0$) and strange (K$_\mathrm{S}^0$, $\Lambda$, $\Xi^-$, and $\Omega^-$)
hadrons, using a data sample of pPb collisions collected by the CMS experiment,
at a nucleon-nucleon center-of-mass energy $\sqrt{s_{_\mathrm{NN}}} =$ 8.16
TeV. A significant positive $v_2$ signal from long-range azimuthal correlations
is observed for all particle species in high-multiplicity pPb collisions. The
measurement represents the first observation of possible long-range
collectivity for open heavy flavor hadrons in small systems. The results
suggest that charm quarks have a smaller $v_2$ than the lighter quarks,
probably reflecting a weaker collective behavior. This effect is not seen in
the larger PbPb collision system at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV, also
presented.
