if they are wood you just add an extra 1" strip to head ...

I just purchased a French doors to replaced my current French doors at my office room. But just find out the height on doors are 1 inch short by my mistake. For example, my current doors are 24 W x 79.5 H and new doors are 24 W x 78.5 H.

Is any one could you please advise me how can I try to make up for these 1 inch short on my doors' height? Thank you so much!