IFRS 15 Step 3 the existence significant financing component in the contract

A vendor (a construction company) enters into a contract with a customer to supply a new building. Control over the completed building will pass to the customer in two years time (the vendor’s performance obligation will be satisfied at a point in time). The contract contains two payment options. Either the customer can pay CU 5 million in two years time when it obtains control of the building, or the customer can pay CU 4 million on inception of the contract. The customer decides to pay CU 4 million on inception.
The vendor concludes that because of the significant period of time between the date of payment by the customer and the transfer of the asset (the completed building) to the customer, together with the effect of prevailing market rates of interest, that there is a significant financing component.The interest rate implicit in the transaction is 11.8%. However, because the vendor is effectively borrowing from its customer, the vendor is also required to consider its own incremental borrowing rate which is determined to be 6%.

The accounting entries required are as follows:
Contract inception:
CU ‘000 CU ‘000
Cash 4,000
Contract liability 4,000
Recognition of a contract liability for the payment in advance

Over the two year construction period:
Interest expense 494
Contract liability 494
Accretion of the contract liability at a rate of 6%

At the date of transfer of the asset (the building) to the customer:
Contract liability 4,494
Revenue 4,494

Could you please show me the working on how to work out the interest expenses of 494?