mat0  --  Simple matrix with rows and columns missing.
40	real
10	10	2
10	20	-1
20	10	-1
20	20	3
20	30	-1
30	20	-1
30	30	3
30	40	-1
40	30	-1
40	40	3
0	00	0
0
0
0
0
0
0
0
0
0
34
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0