Л20
ДО ЛАМПОЧКИ кому
highly collPrepPInvarsubj-compl with быть0 (
subj: any noun, often это, все, все это)) the person or thing in question does not matter at all to
s.o. , does not interest
s.o. in the least
X Y-y до лампочки = Y couldn't (could) care less about X
Y couldn't care a snap about XY doesn't (couldn't) give a damn (a hoot, a fig) about XY doesn't care at all (about X).