Css: Padding : one, two and three values given?!

• If four values are given, they apply to top, right, bottom, and left padding, respectively.
• If one value is given, it applies to all sides.
• If two or three values are given, the missing values are taken from the opposite side.

For example, the following rule sets : p { padding: 2em 4em 5em }
the top padding to 2em, 
the right padding to 4em,
the bottom padding to 5em, and
the left padding to 4em: