Fill up the gap with proper group of alphabets. IKM, JLN, KMO, ____

Pattern followed is :-

I ---->(+1)  = J  ---->(+1)  = K ---->(+1)  = L


K ---->(+1)  = L ---->(+1) = M ---->(+1)  = N


M ---->(+1)  = N ---->(+1)  = O ---->(+1)  = P

Ans :- LNP