1 2 3A |_|_|_| B |_|_|_| C |_|_|_|

- The product of the numbers in row C is twice the sum of the numbers in row C.
- The product of the numbers in column 3 is twice the sum of the numbers in column 3.
- If you ignore column 1, all the columns have even products.
- If you take the six-digit number C3 B3 B1 C1 A3 B2 and multiply it by 3, you get the six-digit number B3 B1 C1 A3 B2 C3.

Try to figure it out without using a computer program.