Atul can complete a piece of work in 'c' days by working 'e' hours per day. Balwinder can complete the same work in 'f' days by working 'g' hours per day. If each of them reduces his working hours by 4 hours, each of them would take 5 days more to finish the work. How long would it take to complete the work, if Atul and Balwinder started working together such that Atul worked for 'e' hours per day and Balwinder worked for 'g' hours per day? It is to be noted that 'c', 'e', 'f' and 'g' are distinct natural numbers and 'e', 'g' < 16.