  A system of Bethe-Ansatz type equations, which specify a unique array of
Young tableau responsible for the leading contribution to the Nekrasov
partition function in the $\epsilon_2\rightarrow 0$ limit is derived. It is
shown that the prepotential with generic $\epsilon_1$ is directly related to
the (rescaled by $\epsilon_1$) number of total boxes of these Young tableau.
Moreover, all the expectation values of the chiral fields $\langle \tr \phi^J
\rangle $ are simple symmetric functions of their column lengths. An entire
function whose zeros are determined by the column lengths is introduced. It is
shown that this function satisfies a functional equation, closely resembling
Baxter's equation in 2d integrable models. This functional relation directly
leads to a nice generalization of the equation defining Seiberg-Witten curve.
