Vaqt limiti: 1 sekund
Xotira limiti: 64 MB
Recently in Farland, a
country in Asia, a famous scientist Mr. Log Archeo
has discovered ancient pyramids. But unlike those in Egypt and Central America,
they have triangular (not rectangular) foundation. That is, they are
tetrahedrons in mathematical sense. In order to find out some important facts
about the early society of the country (it is widely believed that the pyramid
sizes are in tight connection with Farland ancient
calendar), Mr. Archeo needs to know the volume of the
pyramids. Unluckily, he has reliable data about their edge lengths only.
Please, help him!
Input
The file contains six positive integer numbers not
exceeding 1000 separated by spaces, each number is one
of the edge lengths of the pyramid ABCD. The order of the edges is the
following: AB, AC, AD, BC, BD, CD.
Output
A real number - the volume printed accurate to four
digits after decimal point.
Samples
№ |
Input |
Output |
1 |
1 1 1 1 1 1 |
0.1179 |
2 |
1000 1000 1000 3 4 5 |
1999.9937 |
Text from: acm.sgu.ru