Place the eight numbers 1 to 8 into the 6x6 grid, such that at least one number appears in each row and column. Draw a single closed path through all squares (moving up, down, left or right). After passing through a number, the length of the path must be equal to that number when reaching the next number. The numbers must be visited in numerical order, returning to the "1" eight squares after visiting the "8". For example, the "5" will be visited exactly four squares after the "4". Other than the "1" adjacent to the "2", no numbers may be in neighboring squares, not even diagonally.
Source: Original.