In a system two particles of masses m₁ = 3 kg and m₂ = 2 kg are placed at certain distance from each other. The particle of mass m₁ is moved towards the center of mass of the system through a distance 2 cm. In order to keep the center of mass of the system at the original position the particle of mass m₂ should move towards the center of mas by the distance ________ cm.