If ABCDEF is a regular hexagon with its center at 0, then the value of ¯¯¯¯¯¯¯¯AB+¯¯¯¯¯¯¯¯AC+¯¯¯¯¯¯¯¯¯AD+¯¯¯¯¯¯¯¯AE+¯¯¯¯¯¯¯¯AF