In "Princess Pearl", the swallow Ban Mingjie Yongqi helps Wei Zi buy a guzheng. Which episode is it?

It's the 82nd episode. Where is the new Princess Huanzhu? When he arrived in Luoyang, Xiao Jian invited his friends to join the list of famous doctors and borrowed a quadrangle. Yongqi Benmingjie, a swallow, went to buy materials, but spent money to buy a piano for Wei Zi. Wei Zi played a song for Erkang and everyone. Xiao Jian asked the price of the piano, and three people said different things. Xiao Jian pretended to be angry at spending too much money and let them make their own money.