  We present a mixed quantum-classical approach to strong-field ionization - a
semiclassical two-step model with quantum input. In this model the initial
conditions for classical trajectories that simulate electron wave packet after
ionization are determined by the exact quantum dynamics. As a result, the model
allows to overcome deficiencies of standard semiclassical approaches in
describing the ionization step. The comparison with the exact numerical
solution of the time-dependent Schr\"{o}dinger equation shows that for
ionization of a one-dimensional atom the model yields quantitative agreement
with the quantum result. This applies both to the width of the photoelectron
momentum distribution and the interference structure.
