Logan's father receives a delivery of 50 cartons for his milk business, with each carton containing 20 jars of milk. In a particular week, he received 20 cartons less than usual. During offloading, he found that 3 jars in each of 5 cartons were damaged, and one entire carton was completely damaged. How many jars of milk were good for sale that week? Let's think step by step and output the final answer within \boxed{}.
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