The mass of 0 can be measured by observing the reaction + p 0 + n

Question:

The mass of π0 can be measured by observing the reaction π– + p → π0 + n at very low incident π– kinetic energy (assume it is zero). The neutron is observed to be emitted with a kinetic energy of 0.60MeV. Use conservation of energy and momentum to determine the π0 mass.