Option Strict On

Module Module1
    Sub Main()
        'let'
        Dim R As Long = CLng(Console.ReadLine())

        'var'
        Dim ans As String

        Select Case R
            Case Is < 1200
                ans = "ABC"
            Case Is < 2800
                ans = "ARC"
            Case Else
                ans = "AGC"
        End Select

        Console.WriteLine(ans)

    End Sub


End Module
