Use IF condition for visible parameter in formula Revit family error

[mr.engineer.aec]

 Hi guys,

I have new family which need to fill value A1 (type: text) in "Input text". From it, Element 1 is visible and A2, A3, A4... same that.
My family under pic.

How can i solve this issue ?
Thank in advance

[ToanDN]

Text cannot be used to drive a formula. Use an Integer or Number parameter instead. For example:
Input = 1, 2, 3 instead of A1, A2, A3

[mr.engineer.aec]

 Hi @ToanDN 

Thank for your help.

 If Revit can push type of parameter: Text, in formula so really amazing