There are three containers, the first holds 3000ml of water, the second holds 2500ml of water, and the third holds 3500ml of water. Is the water in the three containers combined more or less than 1 liter? Explain with calculations.
有三个容器，第一个装水3000毫升，第二个装水2500毫升，第三个装水3500毫升．这三个容器里的水合起来比1升多还是比1升少？用计算说明．
<result>1</result>