Ampere's circuital law

The diagram below shows a bent wire $a \rightarrow b \rightarrow c \rightarrow d$ situated in z-x plane. A current $I_0$ flows in the direction shown.

An imaginary loop $PQRS$ is placed in the x-y plane as shown below.

Calculate $\displaystyle \oint \vec{B} \cdot \vec{d \ell}$ over the loop $PQRS$ due to current flowing in the bent wire $abcd$ . If the answer is of the form $\dfrac{\mu_0 I_0}{n}$ , where $n$ is a positive integer, enter your answer as the value of $n$ .