IFRS 9

Page 144,
illustration – an entity raises finance by issuing $600,000 4% debentures, redeemable in 3 years’ time at a premium of $33,367. You are told that the effective rate of interest is 7%. No election has been made to treat the liability at FVTPL so it will be accounted for on an amortised cost basis. Issue costs of $20,000 were incurred.

My question is, how did the figure of $33,367 come about?
How was it calculated? I understand the solution and the subsequent measurement, but I can’t understand how we initially calculated the premium.

Thankyou