In the second and third dice 1 and 3 are common in both dice. The second dice is rotated 180 deg clockwise on the other adjacent side of 1, 3 is 4. In the first and third dice 1 and 4 are common in both dice. The first dice is rotated 90 deg anti-clockwise on the other adjacent side of 1, 4 is 3. 6 rarr 4 2 rarr 3 1 rarr 5