An incompressible fluid is flowing between two infinitely large parallel plates separated by $5 \mathrm{mm}$ distance. The bottom plate is stationary and the top plate is moving at a constant velocity of $5 \mathrm{~mm} / \mathrm{s}$ in the direction parallel to the bottom plate. The flow of the fluid between the plates is steady, two-dimensional, laminar, and the variation of fluid velocity is linear between the plates. A square fluid element of $1 \: \mathrm{mm}$ side is considered at equal distance from both the plates in the flow field such that one of its sides is parallel to the plates. The magnitude of circulation in $\mathrm{mm}^{2} / \mathrm{s}$ (in integer) along the edges of the square fluid element is $\_\_\_\_\_\_$
