The calculated distance (air line) between Brandýs nad Labem-Stará Boleslav and Most is approximately 50 miles respectively 81 kilometers.
By car or train, the actual journey to Most is certainly longer, as only the direct route (as the crow flies) between Brandýs nad Labem-Stará Boleslav and Most has been calculated here.
Air line (approximately)
81 kilometers
44 nautical miles