create a selectable list with a default value based on a formula

I am trying to create a list with a default value based on the date, but I would like to be able to change it after the formula fills it in with a standard drop down list. The formula below creates a list but it is not selectable after the fact. Ideally the formula will default to "received" if the year is even and "N/A" if it is odd but would also allow this to be changed.

//calculates if training needs to be completed based on the year and even/odd status of the training and then selects the appropriate text to place in the field
If(
//converts [date completed] to texts and looks at the rightmost character and if it is even lists received then N/A. If not lists N/A then received
//you should be able to then select the second field if it is not correct but this is not working.
Right(ToText([date completed]),1)<>"0",List("\n","Received","N/A"),

Right(ToText([date completed]),1)<>"2",List("\n","Received","N/A"),

Right(ToText([date completed]),1)<>"4",List("\n","Received","N/A"),

Right(ToText([date completed]),1)<>"6",List("\n","Received","N/A"),

Right(ToText([date completed]),1)<>"8",List("\n","Received","N/A"),

List("\n","N/A","Received"))

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Dante Tognoli
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