SSC CHSL 4 Mar 2018 Shift 3 Paper

Series : CX, EV, GT, IR, ?
The pattern followed in each letter of the terms is :
1st letter : C (+2 letters) = E (+2 letters) = G (+2 letters) = I (+2 letters) = K
2nd letter : X (-2 letters) = V (-2 letters) = T (-2 letters) = R (-2 letters) = P
Thus, missing term = KP