How to auto-sum groups of cells?

[Helios9]

Hello forum. I'm hoping someone out there can help me with this. I have a long column of numbers, all grouped into threes and fours, like this:

3
1
0

-6
-2
49

6
-50
-3
2

65
69
78
3

4
-1
-9
54

3
2
3
77

I'm looking for a way to way to auto-sum each group without having to do them individually. The result I'm looking for is like this:

3
1
0
4
-6
-2
49
41
6
-50
-3
2
-45
65
69
78
3
215
4
-1
-9
54
48
3
2
3
77
85

Thanks in advance.

 

[RSXchin]

Got it. Forgot to say "Range" once

Sub Autosum_all()
Dim TotalCell As Long, StartCell As Long, i As Long
lastrow = Cells(Rows.Count, 1).End(xlUp).Row
    For i = lastrow + 1 To 1 Step -1
        If Cells(i, 1) = "" Then
            If TotalCell = 0 Then
                TotalCell = i
            Else
                StartCell = i
                Cells(TotalCell, 1) = Application.WorksheetFunction.Sum(Range(Cells(StartCell, 1), Cells(TotalCell - 1, 1)))
                TotalCell = StartCell
                StartCell = 0
            End If
        End If
    Next i
    Cells(TotalCell, 1) = Application.WorksheetFunction.Sum(Range(Cells(1, 1), Cells(TotalCell - 1, 1)))
End Sub