An Approach to N=4{\cal N}=4 ADE Gauge Theory on K3

We propose a recipe for determination of the partition function of ${\cal N}=4$ $ADE$ gauge theory on $K3$ by generalizing our previous results of the SU(N) case. The resulting partition function satisfies Montonen-Olive duality for $ADE$ gauge group.Comment: 28 pages, Latex, enlarged published versio