  A measurement with high statistics of the differential energy spectrum of
light elements in cosmic rays, in particular, of primary H plus He nuclei, is
reported. The spectrum is presented in the energy range from $6$ to $158$ TeV
per nucleus. Data was collected with the High Altitude Water Cherenkov (HAWC)
Observatory between June 2015 and June 2019. The analysis was based on a
Bayesian unfolding procedure, which was applied on a subsample of vertical HAWC
data that was enriched to $82\%$ of events induced by light nuclei. To achieve
the mass separation, a cut on the lateral age of air shower data was set guided
by predictions of CORSIKA/QGSJET-II-04 simulations. The measured spectrum is
consistent with a broken power-law spectrum and shows a kneelike feature at
around $E = 24.0^{+3.6}_{-3.1} $ TeV, with a spectral index $\gamma = -2.51 \pm
0.02$ before the break and with $\gamma = -2.83 \pm 0.02$ above it. The feature
has a statistical significance of $4.1 \, \sigma$. Within systematic
uncertainties, the significance of the spectral break is $0.8 \, \sigma$.
