Literature Reference: 行舟闻商估，宿在枫林下。——《杂曲歌辞 古别离二首 一》 作者：李端 The boatman hears the merchants' voices, lodging beneath the maple trees. Source from 'Miscellaneous Songs: Ancient Parting I', by Li Duan.
商: Merchant, marketplace. Also refers to a surname.
估: Estimate, to roughly calculate or infer.
Meaning: The term 'Shang Gu' symbolizes merchants and travelers, embodying the spirit of enduring hardships and pursuing dreams.