if ch.is_digit(10)
{
    MenuAnswer::PageNumber
}

else
{
    match ch
    {
        'a' => MenuAnswer::AddNote,
        'e' => MenuAnswer::EditNote,
        'f' => MenuAnswer::FindNotes,
        'd' => MenuAnswer::DeleteNotes,
        'r' => MenuAnswer::RemakeFile,
        'p' => MenuAnswer::ChangePassword,
        _ => MenuAnswer::Nothing
    }
}