Your basis in the stock your father gifted you is:
either of the following:

1. If you sell the stock at a gain, your Basis is
the same as your dads cost in the stock.
or

2. If you sell the stock at a loss, your basis is
the lesser of:
a/ your fathers cost in the stock -or-
b/ the fair market value of the stock at
the time he gave it to you.

GOOD LUCK

PS For capital gain treatment of the stock, you
are considered to own the stock from the date
your dad purchased it.