Sub test()
Dim i%, ligneDebut%, LigneFin%
For i = 3 To 58
If Cells(i, 3).MergeCells Then
LigneFin = Cells(i, 3).Cells(Cells(i, 3).MergeArea.Rows.Count, 1).Row
ligneDebut = Cells(i, 3).Cells(1, 1).Row
End If
If ligneDebut <> LigneFin Then MsgBox Cells(ligneDebut, 3).Address: Exit For
Next i
End Sub