On the analytic functions

Let $\Omega$ be a connected bounded domain on the complex plane, $S$ be its boundary, which is closed, star-shaped, $C^1$-smooth, and $H(\Omega)$ is the set of analytic (holomorphic) in $\Omega$ functions. The aim of this paper is to prove that an arbitrary $f\in L^1(S)$, satisfying the condition $\int_Sf(s)ds=0$, can be boundary value of an $f\in H(\Omega)$.