$\int \int_{\int\limits_{\iint \iint_{\iint\limits_{\iiint \iiint_{\iiint\limits_{\oint \oint_{\frac{\tfrac{\mathrm{d}t \frac{\mathrm{d} y}{\mathrm{d} x} \partial t \frac{\partial y}{\partial x} \nabla\psi \frac{\partial^2}{\partial x_1\partial x_2}y \cfrac{1}{a + \cfrac{7}{b + \cfrac{2}{9}}} =c }{hh} }{hh} }^{hh} }^{hh} }^{hh} }^{hh} }^{hh} }^{hh} }^{hh}$