sherlock holmes the mystery of the mummy

i am new to this, i have just started the game and i'm already stuck i have tried to enter the numbers from each mummy into the opening in the wall where it says OK,NK,MK AND LD what am i doing wrong, please help.

it is the last set of dates on the mummy's
ok 2200
mk 1650
nk 1069
ld 0332