A precision instrument package $(m = 1 \: kg)$ needs to be mounted on a surface vibrating at $60 \: Hz$. It is desired that only $5\%$ of the base surface vibration amplitude be transmitted to the instrument. Assume that the isolation is designed with its natural frequency significantly lesser than $60 \: Hz$, so that the effect of damping may be ignored. The stiffness (in $N/m$) of the required mounting pad is _____