Module Module1

    Sub Main()
        Dim n As Integer
        Dim i As Integer
        Dim flag As Boolean
        For n = 1 To 50
            flag = True
            For i = 2 To n / 2
                If n Mod i = 0 Then
                    flag = False
                End If
            Next
            If flag Then
                Console.WriteLine(n)
            End If
        Next
        Console.ReadLine()
    End Sub

End Module