How Sheriff Tiraspol found themselves in a Champions League group  with Real Madrid and Inter Milan? 

Fotbal Club Sheriff, commonly known as Sheriff Tiraspol or simply Sheriff, is a Moldovan football club based in Tiraspol, a city located in the de jure unrecognized Pridnestrovian Moldavian Republic.

Real Madrid Club de Fútbol, commonly referred to as Real Madrid, is a Spanish professional football club based in Madrid. Founded on 6 March 1902 as Madrid Football Club, the club has traditionally worn a white home kit since inception. 

Football Club Internazionale Milano, commonly referred to as Internazionale or simply Inter, and known as Inter Milan outside Italy, is an Italian professional football club based in Milan, Lombardy. Inter is the only Italian side to have always competed in the top flight of Italian football since its debut in 1909.