Public Class Form1
    Dim arrText() As String
#Region "Functions"
    Function check(ByVal result) 'Checking the result
        Select Case result
            Case result = NumericUpDown1.Value = False 'result isn't same as our chosen result
                Return False
            Case result = NumericUpDown1.Value = True 'result is same as our chosen result
                Return True
        End Select
    End Function
    Function count() 'counting the X
        Dim result As Double
        Dim MathStr As String = String.Empty
        Dim x As Integer
        For x = 0 To 1000 'Counting with numbers 0 to 1000
            For i As Integer = 0 To UBound(arrText)
                MathStr &= arrText(i) & If(i < UBound(arrText), "", "x")
            Next
            result = New DataTable().Compute(MathStr, Nothing) 'Counting
            Select Case check(result) 'checking
                Case True 'if the result equals our chosen result
                    Return x 'returns the lucky number
                    Exit Function
                Case Else
            End Select
        Next
    End Function
#End Region
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        arrText = TextBox1.Text.Split("x")

        CheckForIllegalCrossThreadCalls = False
        Dim t As New Threading.Thread(AddressOf count)
        t.IsBackground = True
        t.Start()
        ListBox1.Items.Add(count())
    End Sub
End Class