Retained Earnings

Good Afternoon Sir,
Sir i have a doubt to clear
Sir if we are Aquiring on 1 Feb And our income statement is of 30th Sep
And we are given the adjustment of retained earnings ” At acquisition the retained earnings of both parent ans subsidiary are given” then when we calculate the goodwill on aquisition we need the pre aquisition amounts rgt sir?
So the profit for the year of subsidiary will we add to retained earnings or substract from retained earnings?And by how many months for both the case?
Plz clear my this doubt sir…Ur help will be highly appreciated .
Thank you
Best regards