# What is *volume*?

**Volume**is a measure of the amount of three-dimensional space occupied by an object. The volume of a container is generally understood to be the capacity of the container; i.e., the amount of fluid (gas or liquid) that the container could hold, rather than the amount of space the container itself displaces.

## Input

**Milliliter**is defined as one-thousandth of a litre, and also often referred to by the SI derived unit "cubic centimeter".

## Output

**Cubic Kilometer**is the volume of a cube with edge length of one kilometer (1000 m), which is equal to one billion cubic meters.