#[]
0
#[0, 1, 2, 3]
#[10, 11, 12, 13]
4
#[10, 11, 12]
#[10, 11, 12, 13, 100]
#[10, 11, 12]
#[3, 4, 5, 6]
#[2, 3]
#[]
#[]
#[3, 4]
#[4, 3, 2, 1]
#[]
#[3, 2, 1]
#[2, 4]
#[2, 4]
#[1, 3, 5]
#[3, 4]
#[]
#[1, 2, 3, 4]