A sample of an ideal gas is taken through the cyclic process \( ABCA \) as shown in figure. It absorbs, \( 40 \, \text{J} \) of heat during the part \( AB \), no heat during \( BC \) and rejects \( 60 \, \text{J} \) of heat during \( CA \). A work of \( 50 \, \text{J} \) is done on the gas during the part \( BC \). The internal energy of the gas at \( A \) is \( 1560 \, \text{J} \). The workdone by the gas during the part \( CA \) is:
