Fifteen Yandex Game

The game "Fifteen Yandex" - based on the classic version of the game of 15, where all the rules are close to the original. Initially, fifteen was a pocket game, which was a square box with square knuckles. On the bones drawn numbers from 1 to 15. The player must move the knuckles across the playing field, using an empty cell to arrange all the numbers downwards in ascending order. The counting starts from the top left cell and goes to the right. In total, on the playing field, there are 4 rows of 4 cells, for a total of 16 cells for 15 knuckles. The task would not seem difficult, but after the start of the game and after setting the first two rows of digits, the real puzzle begins.