# 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

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

## Output

**Imperial Gallon**is defined as exactly 4.54609 litres (277.4194 cubic inches). It is used in some Commonwealth countries.