Trying to do chem homework and do not know how to work this problem. Help please!!?

A chunk of lead at 80.4�C was added to 200.0 g of water at 15.5�C. The specific heat of lead is 0.129 J/g�C, and the specific heat of water is 4.18 J/g�C. When the temperature stabilized, the temperature of the mixture was 18.9�C. uming no heat was lost to the surroundings, what was the m of lead added?