Answer: 1470 seconds
46. As shown in the figure, the side length of the equilateral triangle is 200 meters. Person A starts from point $A$, and person B starts from point $B$, both moving in a clockwise direction along the sides of the equilateral triangle. Person A walks 100 meters per minute, and person B walks 80 meters per minute. At each vertex, they both spend 15 seconds turning. After $\qquad$ seconds, person A catches up with person B for the first time.