Consider a process in which a system expands against a constant external pressure of 0.8 atm to a final volume of 41 L. During this process, the system absorbs 581 J of heat from the surroundings, and the energy of the system increases by 49 J. What was the initial volume (in L) of the system? (Round your answer to the nearest tenth. For example, 12.345 would be entered as 12.3)