Distribute a total value evenly to an amount of cells considering certain conditions

Hi to all,

I wonder if someone could help me with a VBA code (formula) or excel formula in order calculate a distribution:

EJEMPLO.png

As shown in the image, i want to make a distribution of a total value between A to F (B2: F2),

The formula should consider:

1) Distribute the amounts considering the demand as a priority.
2) It should distribute in a way where every Segment A to F receives 1 unit in order till the total value stocks out.
3) When a DEMAND is fullfilled it should pass to the next Segment.
4) ONLY when all demands are fullfilled it should asign evenly 1 unit to all segments until it stocks out.

Example:

Total value = 6

The distribution should start with

E =1 then
D= 1 then
C= 1 then
B= 1 then
A= 1 till now 5 units are asgined then it should start with E again

Final result:

E =2
D= 1
C= 1
B= 1
A= 1

Thank you!