Let f:C→C be a function such that
f(z+ω1)=f(z),f(z+ω2)=f(z)
where ω1,ω2∈C\{0} and ω1/ω2 is not real. Show that if f is analytic on C then it is a constant. [Liouville's theorem may be used if stated.] Give an example of a non-constant meromorphic function which satisfies (1).