Get column with difference

Hello everybody,

I make a package SSIS. who compare two table with same column. and I want to create derived column with the name of column wich I have a difference.( Foreach difference I have a new row with the name of column and two other column with v1_value and v2_value)

And I have error in expression : [Column1_v1] !=[Column1_v2]? "Column1":([Column2_v1]  != [Column2_v2]? "Column2":([Column3_v1]  != [Column3_v2]? "Column3")).

Can you see the  issue in this expression or I should use another compenent .

thanks for your time.