certain county was hit by floods in 1998 and only harvested 201.6 tons of grain, which was 40% less than the previous year. How many tons of grain were harvested in the previous year?
某县于九八年受涝灾，只收粮食201.6吨，比前年减产40%，前年收粮食多少吨？
<result>339</result>