called with [1, 3, 8, 4, 5]
called with [1, 3]
called with [1]
called with [3]
returning [1, 3] 0
called with [8, 4, 5]
called with [8]
called with [4, 5]
called with [4]
called with [5]
returning [4, 5] 0
returning [4, 5, 8] 2
returning [1, 3, 4, 5, 8] 2
2