From Codeforces. Perpendicular line construction. Solve the geometry problem "Perpendicular Segments".
Examples
Input:[1,2,3]
Output:0
Input:[2,3,4]
Output:0
Hints
Two segments are perpendicular iff the dot product of their direction vectors is zero: `(Bx-Ax)*(Dx-Cx) + (By-Ay)*(Dy-Cy) == 0`.
Compute direction vectors `AB = (Bx-Ax, By-Ay)` and `CD = (Dx-Cx, Dy-Cy)`. The order of endpoints on each segment does not matter — reversing flips the sign but preserves the dot product.
Use 64-bit integers (long long in C++, BigInt in Python) for the dot product computation to avoid overflow on coordinate products.
Perpendicular Segments
**From Codeforces.** Perpendicular line construction. Solve the geometry problem "Perpendicular Segments".