A formal language is used to precisely define a Finite State Machine.
A machine M consists of:
Q: the set of states,
Σ: the alphabet of the machine - all symbols the machine can process,
s0: the set of initial states of the machine
F: the set of the machine's accepting states.
δ: The set of transitions the machine allows, with each transition in the form (source state, input symbol, end state).

Construct the Finite State Machine defined by

Q = {1,2,3,4}
Σ = {a,b,c}
s0 = {1}
F = {3,4}
δ = {(1,a,2),(2,b,3),(2,c,4),(3,b,2)}