2
6
buy 10 shares at 100
sell 1 shares at 120
sell 20 shares at 110
buy 30 shares at 110
sell 10 shares at 99
buy 1 shares at 120
6
sell 10 shares at 100
buy 1 shares at 80
buy 20 shares at 90
sell 30 shares at 90
buy 10 shares at 101
sell 1 shares at 80