1. Let k be an arbitrary cardinality. Show that there exists a tournament Tk=(Vn,En) such that for any coloring f:En→k of the edge set En, there are three different vertices x0,x1,x2∈Vn such thatx0x1,x1x2,x2x0∈Enand ∣{f(x0x1),f(x1x2),f(x2x0)}∣≤2(A tounament is a directed graph such that for any vertices x,y∈Vn,x=y exactly one of the relations xy∈En holds.) (C.19) [A. Hajnal]