What should come in place of the question mark (?) in the given series?

IFP – 30, LHN – 26, OJL – 22, RLJ – 18, ?
In the 1st alphabet, add +3
In the 2nd alphabet, add +2
In the 3rd alphabet, subtract −2
And in the number, subtract −4
Apply the same logic:
RLJ – 18 ?
18 , 12, 10 = 21, 14, 8 14
So the answer is UNH – 14