In a certain code language, 'MEDIUM' is coded as 'LDCGSK'. What is the code for 'PREFER' in that code language?

OQDDCP

The place value of respective letters are:

M  E  D  I  U  M        L  D  C  G  S   K

13 5  4  9 21 13      12 4  3   7  19 11

The code used here is 1 is subtracted from first three letters and 2mis subtracted from last three 

Thus, the code for PREFER is- 

16  18  5  6  5  18      15  17  4  4  3  16

 P    R   E  F  E   R        O  Q   D  D  C  P 

The place value of the respective letters are