A high tower appeared on an aerial photograph taken at 1000 m above mean sea level with a camera lens of 15 cm focal length. The radial distances of the top and bottom images of the tower from principal point of photograph are 92.6 mm and 78.3 mm, respectively. If the average elevation of terrain is 300 m above mean sea level, then the height of the tower above ground is _________ m (rounded off to the nearest integer).