A circular ring of small cross-sectional area ‘a’ is placed horizontally in a region where a uniform vertical (upward) magnetic field ${\text{B}}_0$ exists. Radius of the wire is R and current ${\text{I}}_0$  in wire is in anticlockwise direction as shown in figure. The Young’s modulus of the material of the ring is Y. In steady state the elastic potential energy in the ring comes out to be $\text{U=}\frac{{\text{I}}_{\text{0}}^{\text{p}}{\text{R}}^{\text{q}}{\text{B}}_{\text{0}}^{\text{r}}\text{π}}{\text{aY}}$  then find the sum p + q + r.