You are given 9 square pieces (A - I), each one having in each side a number from 1 to 4, positive or negative, as shown:

        +------------+   +------------+   +------------+
        |     +1     |   |     +2     |   |     +1     |
        |            |   |            |   |            |
        |-3   (A)  +4|   |+3   (B)  -1|   |+3   (C)  -2|
        |            |   |            |   |            |
        |     -2     |   |     -4     |   |     -4     |
        +------------+   +------------+   +------------+
        +------------+   +------------+   +------------+
        |     -1     |   |     -2     |   |     +2     |
        |            |   |            |   |            |
        |+2   (D)  -4|   |-4   (E)  +1|   |+1   (F)  -3|
        |            |   |            |   |            |
        |     +1     |   |     +3     |   |     -4     |
        +------------+   +------------+   +------------+
        +------------+   +------------+   +------------+
        |     +3     |   |     -3     |   |     +3     |
        |            |   |            |   |            |
        |-2   (G)  +4|   |+2   (H)  -4|   |-2   (I)  +4|
        |            |   |            |   |            |
        |     -1     |   |     +1     |   |     -3     |
        +------------+   +------------+   +------------+

Your task is to juxtapose them forming a 3x3 grid so that "touching numbers" of each pair of touching pieces (horizontally or vertically) adds to zero.

Note: You are free to rotate the pieces.

Place the nine pieces in a row the same way.

Posted by pcbouhid on 2005-12-12 10:25:44