  We summarize the present knowledge on the non-perturbative hadronic inputs
needed in the analysis of $B^0$-$\bar B^0$ mixing and the CP-violating
parameter $\varepsilon$ of the $K^0$-$\bar K^0$ system. Using this information,
together with the recently determined value of the top-quark mass, we update
the phenomenological constraints on the unitarity triangle.
