25. Astronaut Mark is on a mission on Mars, and his food is running out. Fortunately, Mark is a botany expert, and he makes his own fertilizer to grow potatoes on Mars. Mark plants potatoes on 5 square meters, and after 7 growth cycles, he can harvest 63 kilograms of potatoes. According to this calculation, planting potatoes on 8 square meters, 15 growth cycles can yield $\qquad$ kilograms of potatoes.
$216$