求指教。在lingo 9.0 中运行的时候出现了错误代码11、 在线等！！！

model:max z =2.6*x1+2.9*x2+2.8*x3+3.1*x4+2.8*x5+3.1*x6+2.5*x7+2.8*x8+2.7*x9+3*x10+2.7*x11+3*x12+2.6*x13+2.5*x14+2.6*x15+2.8*x16+2.7*x17+2.8*x18; 11*x1+11*x2+12*x3+12*x4+13*x5+13*x6+10*x7+10*x8+11*x9+11*x10+12*x11+12*x12+9*x13+9*x14+10*x15+10*x16+11*x17+11*x18<2400; x1<=155;x2<=145;x3<=140;x4<=155;x5<=150;x6<=135;x7<=150;x8<=150; x9<=140;x10<=150;x11<=140;x12<=145;x13<=150;x14<=150;x15<=140;x16<=155; x17<=140;x18<=145; @gin(x1);@gin(x2);@gin(x3);@gin(x4);@gin(x5);@gin(x6);@gin(x7);@gin(x8); @gin(x9);@gin(x10);@gin(x11);@gin(x13);@gin(x12);@gin(x14);@gin(x15);@gin(x16); @gin(x17);@gin(x18);end