Two Norm

$$ \rho \frac{\partial \mathbf{u}}{\partial t}+\rho(\mathbf{u} \cdot \nabla) \mathbf{u}=-\nabla P+\rho \mathbf{g}+\mu \nabla^{2} \mathbf{u} $$

int main () {
   printf("Hello World!\n"); 
   return 0;
}

Text text text. Lots of text.