finders keepers

Translations
что нашёл, то моё
Someone found a wallet on the street and said, 'Finders keepers!'
Кто-то нашёл кошелёк на улице и сказал: «Что нашёл, то моё!»
Definitions
A saying that implies that whoever finds something has the right to keep it, often used to justify taking possession of lost or abandoned items.