N=(4,4) 2D supersymmetric gauge theory and brane configuration

We construct type II A brane configuration of N=(4,4) supersymmetric two dimensional gauge theory with gauge group U(1) and Nf hypermultiplets in the fundamental representation. By lifting to M-theory (strong coupling), we can see the origin of the R-symmetry enhancement of the Coulomb branch. One can also find two theories which become equivalent at strong coupling.