  The variations of in- and inter- plane London penetration depths,
$\Delta\lambda(T)$, were measured using a tunnel diode resonator in single
crystals of the intrinsic pnictide superconductor LiFeAs. This compound appears
to be in the clean limit with a residual resistivity of 4 ($T\to0$) to 8
($T_c$) $\mu \Omega\cdot$cm and $RRR$ of 65 to 35, respectively. The superfluid
density, $\rho_s(T)=\lambda^2(0)/\lambda^2(T)$, is well described by the
self-consistent two-gap $\gamma-$model. Together with the previous data, our
results support the universal evolution of the superconducting gap from
nodeless to nodal upon departure from optimal doping. We also conclude that
pairbreaking scattering plays an important role in the deviation of the
low-temperature behavior of $\lambda(T)$ from exponential in Fe-based
compounds.
