1
[2, 3, 4, 5]
some 1
some [2, 3, 4, 5]
[1, 2, 3, 4, 5]
#[1, 2, 3, 4, 5]
#[1, 2, 3, 4, 5]
#[1, 2, 3, 4, 5]
[1, 2, 3, 4, 5, 7]
[0, 1, 2, 3, 4, 5]
[1, 2, 3, 4, 4, 5]
[0, 1, 1, 2, 3, 4, 5, 6]