i.12.1 Vector field circulation

Condition: Calculate the circulation of the vector field \( \bar{a} \) through the closed loop \( \Gamma \), specified parametrically: \[ \bar{a}=y i-x j+z k \] \[ \Gamma:\left\{\begin{array}{c} x=\cos t, y=\sin t \\ z=3 \end{array} \quad t \in[0 ; 2\pi].\right. \]