Max 3100x11+3100x12+3100x13+3800x21+3800x22+3800x23+3500x31+3500x32+3500x33+2850x41+2850x42+2850x43
st
x11+x12+x13<=18
x21+x22+x23<=15
x31+x32+x33<=23
x41+x42+x43<=12

x11+x21+x31+x41<=10
x12+x22+x32+x42<=16
x13+x23+x33+x43<=8

480x11+650x21+580x31+390x41<=6800
480x12+650x22+580x32+390x42<=8700
480x13+650x23+580x33+390x43<=5300

0.1x11+0.1x21+0.1x31+0.1x41-0.0625x12-0.0625x22-0.0625x32-0.0625x42=0
0.0625x12+0.0625x22+0.0625x32+0.0625x42-0.125x13-0.125x23-0.125x33-0.125x43=0
0.125x13+0.125x23+0.125x33+0.125x43-0.1x11-0.1x21-0.1x31-0.1x41=0

x11>=0
x12>=0
x13>=0
x21>=0
x22>=0
x23>=0
x31>=0
x32>=0
x33>=0
x41>=0
x42>=0
x43>=0
end