Compare of two column

Sub RunMe()
Dim mValue As String
Dim x, y, mVar As Integer
Dim Mix As Boolean

x = 2

Do
    mValue = Range("A" & x).Value
    mVar = Range("B" & x).Value
    y = x
    
    Do While Range("A" & x) = mValue
        If mVar <> Range("B" & x).Value Then
            Mix = True
        End If
        x = x + 1
    Loop

    If Mix = True Then
        Range(Cells(y, "C"), Cells(x - 1, "C")).Value = "Mix"
    Else
        Range(Cells(y, "C"), Cells(x - 1, "C")).Value = "Non Mix"
    End If
    
    Mix = False
    
Loop Until Range("A" & x) = vbNullString
End Sub