VTRI  Triangles
English  Vietnamese 
In the plane, given a rectangular grid with sides parallel to the axes of coordinates. The coordinates of the bottomleft corner is (0, 0) and the topright corner is (X, Y).
Your task is to count the number of triangles with integer coordinates lying inside the given grid and having areas equal to an integer S.
Input
A single line consisting of three integers: X, Y, S (1 ≤ X, Y ≤ 30, 1 ≤ S ≤ X*Y/2).
Output
A single integer: the number of triangles with integer coordinates lying inside the rectanglular grid and having areas equal to S.
Constraint
There are 50% of the test cases, corresponding to 50% of the grades, in which 1≤X, Y≤10.
Example
Input 2 1 1 Output 6
hide comments
neha:
20110708 10:36:40
i got result as 0..wat does dis mean? 

martin richardt:
20100207 08:43:38
how to interpret result? 
Added by:  Duc 
Date:  20080419 
Time limit:  0.349s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO NODEJS PERL6 VB.NET 
Resource:  VNOI Marathon '08  Round 1/DivA Problem Setter: Ngô Minh Đức 