I Have a Yin and Yang Pawn Shop

The richest man, Zhang Dafu, pawned 2 billion in starting capital twenty years ago with a life span of 20 years. When the 20 years of pawning expired, he had to pay 40 billion in interest according to the contract. To redeem the life of 20 years, he had to pay 80 billion... After becoming the owner of Yin Yang Pawn Shop, Lin Yang discovered that he could trade anything as long as the weights were equal. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.