called with [1, 4, 6, 5, 5]
called with [1, 4]
called with [1]
called with [4]
returning [1, 4] 0
called with [6, 5, 5]
called with [6]
called with [5, 5]
called with [5]
called with [5]
returning [5, 5] 0
returning [5, 5, 6] 2
returning [1, 4, 5, 5, 6] 2
2