#P14738. [ICPC 2021 Seoul R] Grid Triangle

[ICPC 2021 Seoul R] Grid Triangle

Problem Description

A grid triangle in the 3-dimensional grid system is a triangle of three integral points including the origin (0,0,0)(0,0,0) that satisfy the following property:

There exist three different positive integers X,Y,ZX, Y, Z such that for every pair of the three points of the triangle, you can rotate and translate the cuboid of size X×Y×ZX \times Y \times Z in parallel with the grid system so that the pair are diagonally opposite (and so the farthest way) vertices of the cuboid.

For instance, the triangle of the three points (0,0,0),(1,2,3),(−2,3,1)(0,0,0), (1,2,3), (-2,3,1) is a grid triangle with the cuboid of size 1×2×31 \times 2 \times 3. More specifically, the two points (1,2,3),(−2,3,1)(1,2,3), (-2,3,1) are the diagonally opposite vertices of the cuboid $\{(x,y,z) \mid -2 \le x \le 1, 2 \le y \le 3, 1 \le z \le 3\}$ of size 3×1×23 \times 1 \times 2; the two points (0,0,0),(1,2,3)(0,0,0), (1,2,3) are the diagonally opposite vertices of the cuboid $\{(x,y,z) \mid 0 \le x \le 1, 0 \le y \le 2, 0 \le z \le 3\}$ of size 1×2×31 \times 2 \times 3; and the two points (0,0,0),(−2,3,1)(0,0,0), (-2,3,1) are the diagonally opposite vertices of the cuboid $\{(x,y,z) \mid -2 \le x \le 0, 0 \le y \le 3, 0 \le z \le 1\}$ of size 2×3×12 \times 3 \times 1. Further, all three cuboids are parallel with the grid system.

Write a program to output the number of grid triangles within a bounded 3-dimensional grid system. The grid system is bounded by three given positive integers, A,B,CA, B, C, in such a way that all points of grid triangles should be within $\{(x,y,z) \mid -A \le x \le A, -B \le y \le B, -C \le z \le C\}$.

Input Format

Your program is to read from standard input. The input is exactly one line containing three integers, A,B,CA, B, C (1≤A,B,C≤10,000,0001 \le A, B, C \le 10,000,000).

Output Format

Your program is to write to standard output. Print exactly one line. The line should contain the number of grid triangles in the 3-dimensional grid system bounded by A,B,CA, B, C.

3 3 3
48
3 3 2
16
3 2 2
0