called with [3, 1, 9, 9, 3]
called with [3, 1]
called with [3]
called with [1]
returning [1, 3] 1
called with [9, 9, 3]
called with [9]
called with [9, 3]
called with [9]
called with [3]
returning [3, 9] 1
returning [3, 9, 9] 2
returning [1, 3, 3, 9, 9] 3
3