Counting sort

Alex has found a treasure box in the basement of his old grandma's house. However, the treasure needs a passkey to open. Under the box, Alex found a note with these two lines:

1. The secret key has digits from $1$ to $8$ in ascending order.
2. Use this cumulative array to find the combination: $\{0, 0, 2, 2, 3, 3, 3, 5\}$

What is the passkey? Please enter the number without any space.