CPLEX 8.0.0: optimal solution; objective 303317214
38 dual simplex iterations (0 in phase I)
P [*,*]
:     al   steel    :=
1    1000   4000
2    1200   3800
3    3000   2000
4       0      0
5    1738   3262
6    3044   1956
7       0   4840
8    3390      0
9       0   4262
10   1410   3590
11   4452      0
12      0   4422
;

I [*,*]
:     al   steel    :=
0       0      0
1       0   1600
2       0   3200
3    1600   2500
4       0      0
5       0    500
6    1868      0
7     462   2821
8    1917      0
9       0   1817
10      0   2792
11   2558      0
12   1500   1500
;