Fourth Point
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Given are the (x, y) coordinates of the endpoints of two adjacent 
sides of a parallelogram. Find the (x, y) coordinates of the fourth point.

Input
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The input consists of multiple test cases.  Each test case describes
three points of a parallelogram.  Label the four points of the
parallelogram A, B, C and D when visited clockwise.  Each test
case consists of the (x, y) coordinates of A, B and C.  All
coordinates are in meters, to the nearest mm.  All coordinates are 
between -10000 and +10000.  Input is terminated a line consisting
The input ends with six 0.000 (this case should not be considered).

Output
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For each line of input, print the (x, y) coordinates of the fourth point 
of the parallelogram in meters, to the nearest mm, separated by a single 
space.

Sample Input
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0.000 0.000 0.000 1.000 1.000 1.000
1.000 0.000 3.500 3.500 0.000 1.000
1.866 0.000 3.127 3.543 1.412 3.145
0.000 0.000 0.000 0.000 0.000 0.000

Sample Output
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1.000 0.000
-2.500 -2.500
0.151 -0.398