AFA

I bought shares in a listed bank for a total cost of A. I sold all shares on 30 October 2024 for a price B>A. Since I sold, the share price increased. I think the share price will continue to increase and I regretted selling them and have decided to buy them back. I will buy them back the week commencing November 2024. I don't know in advance what the share price will be but it is likely to be a price C > B > A. When I get to finally sell the shares, how will the capital gain tax be calculated? Which buying price will be used? Can you also let me know if your answer changes in the price studently falls and C