Supply Demand Match Formula with Constraints

I am working on a formula that calculates weekly order quantity based on two inputs "Weekly Max Capacity" And "Demand. Let me provide an example below:

I manually calculated the values in the "order" column, but I am looking for a formula.

Week  Demand  Order  [Weekly Max]
  1                     5
  2             5       5
  3             5       5
  4      5      5       5
  5      3      3       5
  6             5       5
  7     10      5       5
  8             5       5
  9     20      5       5