How to substract current row with next row and then substract the result to next row?

[Manjarigoyal1]

I am trying to substarct the row1 to row2 and then the result will be substracted from row 3 and so on. I am looking for M Query NOT in DAX. Below is the sample data with expected result. Thanks for the help.

Delivery Week	Total Delivery	Expected Result
31-Dec-23	25425	25425
6-Jan	92	25333
13-Jan	172	25161
20-Jan	122	25039
27-Jan	112	24927
3-Feb	218	24709
10-Feb	160	24549
17-Feb	154	24395
24-Feb	135	24260
2-Mar	180	24080
9-Mar	184	23896
16-Mar	151	23745
23-Mar	183	23562
30-Mar	182	23380
6-Apr	171	23209
13-Apr	180	23029
20-Apr	140	22889
27-Apr	21	22868

[AlienSx · Accepted solution]

there are so many running total solutions out there... 

let
    lst = List.Buffer(Table.ToRows(your_table)),
    res = Table.FromList(
        List.Generate(
            () => [i = 0, c = lst{0},  s = c{1}],
            (x) => x[i] < List.Count(lst),
            (x) => [i = x[i] + 1, c = lst{i}, s = x[s] - c{1}],
            (x) => x[c] & {x[s]}
        ),
        (x) => x, 
        {"week", "delivery", "expected"}
    )
in
    res