12. Prime Minister Turtle needs to deliver a batch of pearls to the Dragon King of the East Sea for his birthday. On the first day, he orders "Little Shrimp Soldier" to transport $20 \%$ of the total. On the second day, he orders "General Crab" to transport $80 \%$ of the remaining. It turns out that the second day's transport is 22 tons more than the first day's. This batch of pearls totals $\qquad$ tons.
$50$