Adding 1 everytime i use button vb.net - vb.net

Question

Basically, I need 2 make a student number and after every new entry I put the student number should +1 so 20182(or 3 if male)001 will be 20182(or 3 if male)002 after I push the button and it must keep +1 but once it reaches the 10th registered student the format changes to 20182(3 if male)010.
I have done everything but make the number +1 every time I use the button
so basically the answer must be:
Student Number is 20182001
Surname , Name
contact details
but, I done everything besides the 001, 002,003 till 010 part so if anybody could help I would be thankful
Public Class Form1
Public Number As Integer = 2018000
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim strSurname As String
Dim strFullName As String
Dim strContact As String
Dim strGender As String
Dim x As Integer
'IF statement'
If Me.cboGender.SelectedItem = "Female" Then
Number = 2018300
Else
End If
If Me.cboGender.SelectedItem = "Male" Then
Number = 2018200
Else
End If
'Finding The Student Number'
Dim i As Integer = 0
Do While (i < 1)
i = i + 1
Loop
If i = 201820010 Then
Number = 201800
Else
If i = 201830010 Then
Number = 201800
End if
End If
'Add Items To ListBox'
ListBox1.Items.Add("Student number: " & Number & i)
ListBox1.Items.Add(txtSurname.Text & " , " & txtFullName.Text)
ListBox1.Items.Add(txtContact.Text)
ListBox1.Items.Add("============================================")
End Sub
End Class

Answer 1

Not sure what your code was doing, but based on your requirements:
Public baseFemale As Integer = 20182000
Public baseMale As Integer = 20183000
Public autoNumber As Integer = 0
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim Number as Integer;
autoNumber = autoNumber + 1
If Me.cboGender.SelectedItem = "Female" Then
Number = baseFemale + autoNumber
Else
Number = baseMale + autoNumber
Else
'Add Items To ListBox'
ListBox1.Items.Add("Student number: " & Number & i)
ListBox1.Items.Add(txtSurname.Text & " , " & txtFullName.Text)
ListBox1.Items.Add(txtContact.Text)
ListBox1.Items.Add("============================================")
End Sub
Additionally you may want to check for autoNumber exceeding 999 - but I leave that as an exercise for you.