Oswald and the Ice-Cream Trucks

Problem description Oswald and Daisy got very bored in their hostels so they decided take a walk and to play a game. While walking they can see ice-cream trucks of different colours running past them. Ice-cream trucks are going one after another. The game rules are like this. Firstly Oswald chooses some color A, then Daisy chooses some color B (A≠ B). After each ice-cream truck they update the n