Suppose that 2.6g(mstm) of steam at 120 C(Tstm) is mixed in an isolated massless container(standard atmospheric pressure) with an unknown mass of ice at -10 C (Tice) The system comes to thermal equilibrium at 24.5C (Tf) what is the mass(mice) of the ice?

mstm = 2.6g
Tstm = 393.15K
mice = ?
Tice = 263.15K
Tf   = 297.65K