  An exact incompressible quantum liquid is constructed at the filling factor
$1/m^2$ in square lattice. It supports deconfined fractionally charged
excitation. At the filling factor $1/m^2$, the excitation has fractional charge
$\pm e/m^2$, where $e$ is the electric charge. This model can be easily
generalized to the integer lattice in any $D$ dimensions, where the charge of
excitations becomes $\pm e/m^D$.
