German Fehlende kleinste Zahl ermitteln

Sub QueryMyDeviceName()
    
Dim myDeviceN_trennen() As String     
    For i = 0 To GeneralSettings.SettingsMap.Size-1
        
        For Each myDeviceN As String In GeneralSettings.SettingsMap.Keys
            myDeviceN_trennen = Regex.Split("\|",myDeviceN)
            If     myDeviceN = "MyDeviceName|" & (i+1)Then
                Log(myDeviceN_trennen(0) & " " & myDeviceN_trennen(1))   
                myDeviceList.Add(GeneralSettings.SettingsMap.Get(myDeviceN))   
            End If   
        Next
    Next
End Sub

Dim data2 As Map = CreateMap(1: "K1", 2: "K2", 3: "K3",5:"K5", 7: "K7")
    'Dim data2 As Map = CreateMap(1: "K1", 2: "K2", 3: "K3",4: "K4", 5:"K5", 6: "K6", 7: "K7")
    For i=1 To data2.Size-1  'Achtung Index ab 1 wegen (i-1)
        If data2.GetKeyAt(i-1)-data2.GetKeyAt(i) <-1 Then
            Log("Found first big gap at Index: " & (i-1))
            Log("New Minimun Key is :" & (data2.GetKeyAt(i-1)+1))
            Exit
        End If
    Next