A force of 125N is applied to the free end of the rope thrown over the fixed block in order to evenly lift

A force of 125N is applied to the free end of the rope thrown over the fixed block in order to evenly lift a load weighing 10 kg. What is the efficiency of a non-lower unit?

F = 125 N.
m = 10 kg.
g = 9.8 m / s ^ 2.
η -?
η = (Ap / Az) * 100%, where Ap – useful work, Az – expended work.
Ap = m * g * S, where m is the mass of the load, g is the acceleration of gravity, S is the movement of the load.
Az = F * S, where F is the force with which the rope is pulled, S is the length of the rope that has moved.
η = (m * g * S / F * S) * 100% = (m * g / F) * 100%.
η = (10 kg * 9.8 m / s ^ 2/125 N) * 100% = 78.5%.
Answer: the efficiency of the stationary block η = 78.5%