Multi-Level Parent Summation (BOM type)

Hi, I'm looking for a formula that can sum BOM-style levels, where a higher number (e.g 5) is always a child of a lower number (e.g. 4). I've seen some formulas that are close, but I can't tweak them to get exactly what I want. Hope someone can help!
In the example below, the first column is the level number, the second is the values that will have been entered. The Third column is what i want the formula to calculate.

Level	Child Values	Parent / Total SUMS
0		130
1		43
2	25	25
2		18
3		18
4		18
5	18
1		87
2	27	27
2		60
3	30
3	30
0		115
1	26	26
1		89
2		89