ATPL: The automatic flight control system (AFCS) in an aircraft is coupled to the guidance outputs from an inertial navigation system (INS).The aircraft is flying between inserted waypoints No. 3 (55°00'N 020°00'W) and No.4 (55°00'N 030°00'W).With DSRTK/STS selected on the CDU, to the nearest whole degree, the initial track read-out from waypoint No. 3 will be: