Sarah isn’t super confident with your choice, but she trusts you for some reason. After you pick that free group and start recreating Dini the 3d printer makes a hamster but then no matter what future decisions you make, the unthinkable happens Dini is now half hamster half machine. Scary sci-fi robotics protrude from every limb replacing his fury cuddly physique! You’ll have to try another free group. What do ya pick?
F2 = {e} U S(a) U S(a^-1) U S(b) U S(b^-1)
F2 = {e} U S(a) U S(a^-1) U S(b) U S(b^-1) U S(f) U S(f^-1) U S(j) U S(j^-1)