Problems
The area of quadrilateral
The area of quadrilateral
Find the area of a quadrilateral with vertices A
(x[1]
,y[1]
), B
(x[2]
,y[2]
), C
(x[3]
,y[3]
), D
(x[4]
,y[4]
).
Input data
The coordinates of successive vertices of a quadrilateral are given in a single line. All numbers are integers, not exceeding 100 by absolute value.
Output data
The area of a quadrilateral, rounded to integers.
Examples
Input example #1
1 4 5 4 4 2 2 1
Output example #1
8