Private Sub Worksheet_Change(ByVal R As Range)
If R.Address = "$M$1" Then
Rows("4:13").Hidden = 1
If R <> "" And IsNumeric(R) Then Rows("3:" & 3 + Int(R)).Hidden = 0
Rows("652:655").Hidden = 1
Rows("637:651").Hidden = 1
If R <> "" And IsNumeric(R) Then Rows("637:" & 641 + Int(R)).Hidden = 0
If R <> "" Then Rows("652:655").Hidden = 0
End If
End Sub