Counting cells that are non matching

Hello,

I am trying to come up with a way to sum the total of non matching cells when comparing two columns in two workbooks. So far I have the following, but I am bit confused as to what to do next:

   strRangeToCheck = "F2:F10000"
        x = Worksheets("Contract").Range(strRangeToCheck)
        y = Worksheets("As Built").Range(strRangeToCheck)
        
    'Loop through and do a comparison to add up the cells that aren't identical
        For iRow = LBound(x, 1) To UBound(x, 1)
            For icol = LBound(x, 2) To UBound(x, 2)
                If x(iRow, icol) = y(iRow, icol) Then
                    'cells are identical.
                    'do nothing
                Else: For iRow = LBound(x, 1) To UBound(x, 1)
                        For icol = LBound(x, 2) To UBound(x, 2)
                            If x(iRow, icol) <> y(iRow, icol) Then
                        Range("A8") =

With Range"A8" being the resultant cell.