In the P-V diagram, l is the initial state and F is the final state. The gas goes from I to F by
(i) IAF, (ii) IBF, (iii) ICF. The heat absorbed by the qas:

Heat absorbed in a thermodynamic process is given by:

$\mathrm{\Delta }Q=\mathrm{\Delta }U+\mathrm{\Delta }W$

Here, ΔU is same for all the three processes as it depends only on initial and final states.

But 

$\mathrm{\Delta }{W}_{\mathrm{I}}=+ve,\mathrm{\Delta }{W}_{\mathrm{II}}=0,\mathrm{\Delta }{W}_{\mathrm{III}}=-ve$

or $\mathrm{\Delta }{W}_{\mathrm{I}}>\mathrm{\Delta }{W}_{\mathrm{II}}>\mathrm{\Delta }{W}_{\mathrm{III}}$

then $\mathrm{\Delta }{Q}_{\mathrm{I}}>\mathrm{\Delta }{Q}_{\mathrm{II}}>\mathrm{\Delta }{Q}_{\mathrm{III}}$