76. A barrel water company originally sells a barrel of water for 20 yuan, and now is holding a promotional activity, “Buy 10 barrels and get a 40 yuan voucher, with a chain gift”, meaning that for every 10 barrels of water purchased (10 barrels can be bought with cash, vouchers, or a combination of both), a 40 yuan voucher is given; for every 20 barrels of water, an 80 yuan voucher is given, and so on. Xiaomei's family spent 1000 yuan and can get back the maximum of $\qquad$ barrels of water.
Reference answer: 62