Sub Macro1()
Dim R As Range, L&
With ActiveSheet: Set R = Intersect(.[2:1000000], .UsedRange): End With
L = 1 + R.Rows.Count
With R.Columns(R.Columns.Count + 1)
.FormulaR1C1 = "=1/(RC4<>R" & L & "C4)"
.SpecialCells(xlCellTypeFormulas, 1).EntireRow.Delete
.Delete xlToLeft: End With
End Sub