Two charges 14 μC and -4 μC are placed at (-12 cm, 0, 0) and (12 cm, 0, 0) in an external electric field $\mathbf{E}=\frac{\mathrm{B}}{{\mathrm{r}}^2}$ where $\mathrm{B}=1.2\times {10}^6\mathrm{N}/{\mathrm{cm}}^2$ are r is in metres. The electrostatic potential energy of the configuration is