Light is related to Sun. Sun is related to Earth. Earth is related to Planet. 
Input is the opposite of Output. Output is related to Milk. Milk is related to Water. Water is a type of Utility. 
Light <--RelatedTo--> Sun <--RelatedTo--> Earth <--RelatedTo--> Planet 
Input <--Antonym--> Output <--RelatedTo--> Milk <--RelatedTo--> Water --IsA--> Utility 