\( 2 \, \text{L} \) of \( 0.2 \, \text{M} \) \( \mathrm{H_2SO_4} \) is reacted with \( 2 \, \text{L} \) of \( 0.1 \, \text{M} \) \( \mathrm{NaOH} \) solution, the molarity of the resulting product \( \mathrm{Na_2SO_4} \) in the solution is __________ millimolar. (Nearest integer)