Write a function P3:
A point P on a surface of a cube C which has (0, 0, 0) and (100, 100, 100) as its vertex, with its planes parallel to the planes made by axes.
input parameter: x, y, z which make a point P(x, y, z) be on the surface of C
x, y, z is either an integer or a float.return value: the minimum distance of (x, y, z) to (100, 100, 100) with these following restrictions: