Test 1.  Should print a simple 4 x 3 pattern
P3
4 3
255
255 255 255  0 0 0  255 255 255  0 0 0
0 0 0  255 255 255  0 0 0  255 255 255
255 255 255  0 0 0  255 255 255  0 0 0
Test 2.  Should print a simple 6 x 8 pattern
P3
6 8
5
0 0 0  0 0 0  0 0 0  1 1 1  1 1 1  2 2 2
0 0 0  0 0 0  1 1 1  1 1 1  2 2 2  2 2 2
0 0 0  1 1 1  1 1 1  2 2 2  2 2 2  2 2 2
1 1 1  1 1 1  2 2 2  2 2 2  2 2 2  3 3 3
1 1 1  2 2 2  2 2 2  2 2 2  3 3 3  3 3 3
2 2 2  2 2 2  2 2 2  3 3 3  3 3 3  4 4 4
2 2 2  2 2 2  3 3 3  3 3 3  4 4 4  4 4 4
2 2 2  3 3 3  3 3 3  4 4 4  4 4 4  5 5 5
Test 3.  Should print 669206373 10102
669206373 10102
Test 4.  Should print 1926073387 101484
1926073387 101484