All the 100 sign in and teachers and groups are selected at random.
2 teachers (A&B) teach 1 (C)
then (C) teaches another (D)
C cannot teach A or B
Neither A nor B can teach D since C is teaching D what he learned from A or B.
A&B can be taught by anyone other than C
If there were 6 teachers then
A and B teaches C,
C and D teaches E.
E and F can teach A or they could teach B
E cannot teach C or D
This repeats randomly among the 100
how would you randomize the assignments?