  We confirm by explicit computation the conjectured all-orders iteration of
planar maximally supersymmetric N=4 Yang-Mills theory in the nontrivial case of
five-point two-loop amplitudes. We compute the required unitarity cuts of the
integrand and evaluate the resulting integrals numerically using a
Mellin--Barnes representation and the automated package of ref.~[1]. This
confirmation of the iteration relation provides further evidence suggesting
that N=4 gauge theory is solvable.
