Problem Statement 
 A cuboid is a rectangular solid. Given a few cuboids, which may or may not overlap, you have to find out the total volume enclosed by them. A volume is considered enclosed if it falls completely within at least one of the specified cuboids. A volume that is in between
several cuboids, but not inside any of them, is not considered enclosed.
The input is given as a int[], cuboids. The first 6 elements of cuboids describe the first cuboid, the next 6 the second cuboid and so on. The 6 elements specify the leftbottomfront vertex and then the righttopback vertex. Each vertex is specified by 3 elements which refer to its x, y and z coordinates respectively.
For instance, if cuboids = {0,0,0,1,1,1}, it would mean there is one cuboid whose leftbottomfront vertex is (0,0,0) and whose righttopback vertex is (1,1,1). In this case the volume enclosed would be 1. However, if cuboids = {0,0,0,1,1,1,1,1,1,2,2,2}, it would mean there are two cuboids, one whose leftbottomfront vertex is (0,0,0) and righttopback vertex is (1,1,1), and another whose leftbottomfront vertex is (1,1,1) and righttopback vertex is (2,2,2). In this case, the enclosed volume would be 2. 

Definition 
 Class:  CuboidJoin  Method:  totalVolume  Parameters:  int[]  Returns:  long  Method signature:  long totalVolume(int[] cuboids)  (be sure your method is public) 




Notes 
  The cuboids are always aligned with the grid. In other words, the cuboids are never tilted or twisted with respect to the axes. 
  The x coordinate increases from left to right, the y coordinate from bottom to top, and the z coordinate from front to back. 

Constraints 
  cuboids will contain between 0 and 30 elements, inclusive. 
  The number of elements in cuboids will be a multiple of 6. 
  Each element of cuboids will be between 5000 and 5000, inclusive. 
  As is explained in the problem statement, each cuboid is specified as a block of six elements x1,y1,z1,x2,y2,z2. In each such block, x1 is less than or equal to x2, y1 is less than or equal to y2 and z1 is less than or equal to z2. 

Examples 
0)  
  Returns: 1  There is just one cuboid which is a 1by1by1 cube. Hence, the volume enclosed is 1*1*1 = 1. 


1)  
 {0,0,0,1,1,1,1,1,1,2,2,2} 
 Returns: 2  There are two cuboids, both of which are 1by1by1 cubes. Hence, the volume enclosed is 1*1*1 + 1*1*1 = 2. 


2)  
 {0,0,0,4,4,4,0,0,0,1,1,1}

 Returns: 64  There are two cuboids. One is a 1by1by1 cube and another is a 4by4by4 cube. The volume enclosed is 4*4*4 = 64 as the 1by1by1 cube is completely enclosed within the 4by4by4 cube. 


3)  
 {5000,5000,5000,5000,5000,5000} 
 Returns: 1000000000000  

4)  
 {0,0,0,1,2,3,5,5,5,6,6,6} 
 Returns: 7  

5)  
 
6)  
  Returns: 0  The answer is 0 because "flat" solids enclose no volume. 

