A magician has 300 cards with numbers from 1 to 300 written on them, each number on exactly one card. The magician then lays these cards on a 3×100 rectangle in the following way - one card in each unit square so that the number cannot be seen and cards with consecutive numbers are in neighbouring squares. Afterwards, the magician turns over k cards of his choice. What is the smallest value of k for which it can happen that the opened cards definitely determine the exact positions of all other cards? combinatoricscoding theorybijectionGame Theory