### Instruction:

Extract the cause and effect entities from the following sentence:
Cost efficiency is an issue, and introducing parking space sharing, as it makes it possible to ensure that neither private nor public parking sites are left with unused space

### Assistant:

NOT_RELEVANT: Cost efficiency is an issue, and
CONDITION: are left with unused space
VARIABLE: public parking sites
NEGATION: neither
KEYWORD: as it makes it possible to ensure that
AND: nor
CAUSE_1: introducing parking space sharing
EFFECT_1: private
EFFECT_2: public parking sites are left with unused space


### END
