The basic one-way train fare for a child aged between 3 and 12 years costs half the regular one-way train fare for an adult plus a reservation charge that is the same on the child's ticket as on the adult's ticket. One reserved ticket for an adult costs Tk. 216 and the cost of a reserved ticket for an adult and a child (aged between 3 and 12) costs Tk. 327. What is the basic fare for the journey for an adult?