Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the odd letter-cluster.

FHLQR

FHLQR =  F → (+2) → H → (+4) → L → (+3) → O → (+3) →R (THIS IS ODD)

NKHEB = N → (-3) → K → (-3) → H → (-3) → E → (-3) → B

SPMJG =  S → (-3) → P → (-3) → M → (-3) → J → (-3) → G

UROLI = U → (-3) → R → (-3) → O → (-3) → L→ (-3) → I