From an initial state where the pressure is p$1,$ the temperature is T$1,$ and the volume is V$1,$ water vapor contained in a piston$$cylinder assembly undergoes each of the following processes:

Process $12$: Constant$-$temperature to p$252$p$1.$ Process $13$: Constant volume to p$352$p$1.$ Process $14$: Constant pressure to V$452$V$1.$ Process $15$: Constant temperature to V$552$V$1.$