Three Frequency Assignment

You are assigning radio frequencies to a set of communication towers. To avoid interference, no two towers that directly interfere with each other can share the same frequency. You have exactly 3 frequencies available: "F1", "F2", and "F3".

Given a list of tower names and a list of interference pairs [t1, t2] (bidirectional), determine whether it is possible to assign one of the 3 frequencies to each tower such that no two interfering towers share a frequency. ...