IFRS 2 Share-based payment question

Hi,
PLease help me with the below:

I don’t really understand how the equity-settled share-base payments are calculated.

e.g.:
The share price at the beginning of the year is 100$.
at the beginning of the year it was announced that 10 directors will get 100 shares (10 per person) with a 2 years vesting period if they remain in employment + the share price rise 10%.

at year-end: 5 directors left the company and the share price is 90$.

How much expense should I charge to the P&L at the end of the first year?

Thanks in advance,
Miki