A three-dimensional shape is convex if, for any two points inside it, the line segment joining them lies entirely within the shape. For a set of points X in three-dimensional space, the convex hull of X is the smallest convex shape that contains every point of X.
For example, let X={(0,0,0), (10,0,0), (0,10,0), (0,0,10)}. The convex hull of X is the tetrahedron whose vertices are the points of X. This tetrahedron contains the point (1,1,1), so adding (1,1,1) to X would not change the hull.
Given X, compute the surface area of its convex hull, rounded to the nearest integer.
Note: every face of a convex hull is a polygon. In this problem you may assume that at most 3 points of X lie on any single face of the hull (so every face is a triangle).
The input contains multiple test cases. Each test case begins with an integer n (4≤n≤25), the number of points in X. The next n lines each contain three integers: the x, y, and z coordinates of one point. Every coordinate satisfies −100≤x,y,z≤100.
The input ends with a line containing n=0, which must not be processed.
For each test case, print a single line containing the surface area of the convex hull, rounded to the nearest integer (for example, 2.499 rounds to 2, while 2.5 rounds to 3).
To avoid ambiguity from rounding, the test data is built so that every answer is at least 0.001 away from a rounding boundary (for instance, an area is never exactly 2.4997).