In which issue did Zhang Genyuan teach Nie Li Shuangyu to play the piano?

The fourth question. In the fourth issue of "Heartbeat Signal 5", Zhang Genyuan had only one "mini-date" opportunity for each guest, and invited Nie Li Shuangyu, Shuangyu also invited Zhang Genyuan to play the piano, and Zhang Genyuan played a song "Wedding in Dreams". Zhang Gengen,1born on May 3, 1999, is from Lanzhou City, Gansu Province. High school students study in Lanzhou No.1 Middle School, and the university is new york University.