A     B     C
   +-----+-----+-----+      
 A |     |     |     |    
   +-----+-----+-----+  
 B |     |     |     |        
   +-----+-----+-----+     
 C |     |     |     |  
   +-----+-----+-----+

Complete the crossnumber, using six 3-digit positive integers and having regard to the following clues:

                                            
          ACROSS                               

A. A number that is both a square and a cube.                                 
B. A perfect square                            
C. A perfect square   
                       
           DOWN
   
A. A triangular number.                            
B. A perfect square                     
C. A perfect square