How to add values in excel skipping one column in between?

I need everyone's help on how I can sum all values by skipping one column in between.

Example: I have raw data with numbers from A1 till Z1 I want to add/sum all numbers but skipping one column. Only add A1, A3, A5, and so on (further than Z1).

Thank you for the help.


Or you also try this:
Sum of odd columns:

=SUMPRODUCT((MOD(COLUMN($A$1:$H$1),2)=1)*$A$1:$H$1)

Sum of even columns:

=SUMPRODUCT((MOD(COLUMN($A$1:$H$1),2)=0)*$A$1:$H$1)

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If you want to sum odd/even rows later, you could change COLUMN to the ROW function and apply it to the corresponding cells.