"After Winter".
According to Kugou music data, da da da da da comes from the song "After Winter", original singer: CoCo Li Min, lyricist: Lou Nanwei, composer: Li Zhengfan, arranger: Li Zhengfan , Release date: 1998-01-19.
Part of the lyrics: I am writing to tell you that the weather in Taipei is also good, oh, da da da da da da da, da da da da da, yeah, I received your letter and brought you the latest news, The only surprise in a busy life is like a stimulant. The sun is shining all over the south and Taipei is entering the rainy winter. You said don’t forget it.