Required Information

In a heat engine, $4\mathrm{.}20$ mol of a monatomic ideal gas, Initially at $4\mathrm{.}00$ atm of pressure, undergoes an isothermal expansion, Increasing its volume by a factor of $9\mathrm{.}50$ at a constant temperature of $657\mathrm{.}0$ K $.$ The gas is then compressed at a constant pressure to its original volume. Finally, the pressure is increased at constant volume back to the original pressure.

What is the heat flow into or out of the gas during process $3?$

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