In a certain code language, 'MK - SP' is coded as '–605', and 'AB - TF' is coded as '–194'. How will 'GM - HK' be coded in that language?

-98

A   B   C    D   E    F   G    H    I    J    K    L   M

 ↓    ↓    ↓    ↓    ↓     ↓   ↓    ↓     ↓   ↓    ↓    ↓    ↓

 Z   Y    X   W   V    U   T    S    R   Q   P    O   N

26  25  24  23  22  21  20  19  18  17  16  15  14

**********************************************************

THE LOGIC FOLLOWED HERE IS :

VALUE OF IST LETTER PAIR - VALUE OF IINS LETTER PAIR

AS

MK - SP

M(13) K(11) - S (19) P (16)

1311 - 1916 = - 605

AND

AB - TF

A (1) B (2) - T(20) F (6)

12 - 206 = -194

SIMILARLY

GM - HK

G(7) M(13) - H(8) K(11)

713 - 811 = -98