Does anyone know on how to code on following condition?

[row 1] a blank row
[row 2] 10, which should be equal to the last value in row 3
[row 3] 10
[row 4] a blank row

[row 1] a blank row
[row 2] 23, which should be equal to the last value in row 4
[row 3] 23, which should be equal to the last value in row 4
[row 4] 23
[row 5] a blank row
[row 6] 41, which should be equal to the last value in row 9
[row 7] 41, which should be equal to the last value in row 9
[row 8] 41, which should be equal to the last value in row 9
[row 9] 41
[row 10] a blank row

If the next row [10] is a blank one, then current row [9] is defined to be
the last value.

Does anyone know how to code above condition in excel?
Could anyone give me any suggestion please?
Thank you in advance
Eric