  We show that non-Markovian effects of the reservoirs can be used as a
resource to extract work from an Otto cycle. The state transformation under
non-Markovian dynamics is achieved via a two-step process, namely an isothermal
process using a Markovian reservoir followed by an adiabatic process. From
second law of thermodynamics, we show that the maximum amount of extractable
work from the state prepared under the non-Markovian dynamics quantifies a
lower bound of non-Markovianity. We illustrate our ideas with an explicit
example of non-Markovian evolution.
