The longest hair corresponds to a poem.

White hair three thousands of feet, sorrow like a beard. The poem with the longest hair on the head is the poem in Li Bai's Seventeen Poems of Qiu Pu. The poem is "White hair and three thousands of feet, sorrow is like a beard". This poem means three thousands of feet with white hair, because sorrow is like this. Compare your hair to 3000 feet and describe it as long. Therefore, the poem corresponding to the longest hair is "white hair and three thousands of feet, and sorrow is like a long beard."