  The anomalous line shape of the $\psi(3770)$ state has resulted in some
difficulty in the determination of the $R$ value for the continuum light hadron
production in the resonance energy range. We parameterize the asymmetric line
shape using a Fano-type formula and extract the $R_{uds}$ value to be $2.156\pm
0.022$ from the data of BESIII Collaboration in the energy region between 3.650
and 3.872 GeV. The small discrepancy between experiment and theory is removed.
The cross sections of the $e^+e^- \rightarrow hadrons$ are given by subtracting
the part of continuum light hadron production and are compared to the data of
the $e^+e^- \rightarrow D\bar{D}$ reaction.
