Which term comes next in the following series : YEB, WFD, UHG, SKI……….

Y (Y-2=W) E (E+1=F) B (B+2=D)
W(W-2=U) F (F+2=H) D (D+3=G)
U (U-2=S) H (H+3=K) G (G+2=I)
S (S-2=Q) K (K+4=O) I (I+3=L)
Q O L