Creepy Osciillations (Part 2)

Consider the scenario presented in the picture.

Three point charges (each carrying $+q$ charge and each of mass $m$ ) are symmetrically placed along the circumference of a rigid circular hoop of radius $R$ . Two of them (upper ones in the picture) are fixed in their position while the other can move along the hoop. In the shown situation, the system is in equilibrium. If we slightly displace the lower charge $+q$ from its equilibrium , what will be the angular frequency of the resultant oscillation?

Values and Assumptions:

1) Here $m=1kg$ , $q=1C$ , $R=1m$

2) Coulomb Constant $\frac{1}{4\pi\epsilon_{0}}$ = $1Nm^{2}C^{-2}$

3) Neglect the gravitation acceleration $g$ . [Assume the process is carried out in vacuum]

4) No dissipative force like friction etc. is present.