Shane and Rose are madly in love with each other. To remind Rose of his pure love, Shane wants to send her a ring through post but in their country where burglary is quite prominent, any package that is not locked comes under the risk of being stolen for the contents.
Shane and Rose possesses many padlocks but neither one of them has the other key.
Can you find a way Shane can send the ring to Rose safely?
Shane can use a lockbox that can hold two locks. Shane will put the ring in the box and lock it before sending to Rose. When Rose receives the box, she can add her lock to the box and send it back to Shane.
Upon receiving the box back, Shane can simply take off his lock and send it to Rose again.
