called with [6, 6, 8, 9, 7]
called with [6, 6]
called with [6]
called with [6]
returning [6, 6] 0
called with [8, 9, 7]
called with [8]
called with [9, 7]
called with [9]
called with [7]
returning [7, 9] 1
returning [7, 8, 9] 2
returning [6, 6, 7, 8, 9] 2
2