| (o) | Derivative financial instruments |
The Group uses derivative financial instruments, such as cross currency swap and cross currency option. Such derivative financial instruments are initially recognised at fair value on the date on which a derivative contract is entered into and are subsequently remeasured at fair value. Derivatives are carried as financial assets when the fair value is positive and as financial liabilities when the fair value is negative.
For the years ended December 31, 2017, 2016 and 2015, the Group did not have any derivatives designated as hedging instruments.