Organisation

Salmon loves to be a tidy person. One day, when he looked at the mess that he made after playing with his rubber ducks, he felt awful. Now he wants to clean up his mess, by placing his ducks into boxes. Each rubber duck has a color. There are a total of $N+1$ colors, numbered from $0$ to $N$. Salmon wants to place his $N*K$ ducks into $N$ boxes, each of which can fit $K$ ducks. Each duck should