if you take a look at this input array [1, 3, 7, 5, 2, 3, 5, 6]

the reference answer outputs 6 for the above input.

However, if we use the following action sequence:

```
[1(buy), 3(buy), 7(sell), 5(sell), 2(buy), 3(buy), 5(sell), 6(sell)]
```

9 spent, 23 made, so we get a profit of 14

am I missing something? Or is the reference solution incorrect?