a)
{(3,1),(3,2),(3,3),(3,4),(3,5),(3,6)}
b)
{(1,1),(2,2),(3,3),(4,4),(5,5),(6,6)}
c)
{(2,1),(2,2),(2,3),(2,4),(2,5),(2,6),(1,2),(3,2),(4,2),(5,2),(6,2)}
d)
{(1,6),(2,5),(3,4),(4,3),(5,2),(6,1)}
e)
{(1,1),(1,2),(2,1),(1,3),(2,2),(3,1),(1,4),(2,3),(3,2),(4,1),(1,5),(2,4),(3,3),(4,2),(5,1)}