怎么用LINGO解不出这题

怎么用LINGO解不出这题
min=x1*c1+x2*c2+x3*c3+x4*c4+x5*c5+x6*c6+x7*c7+x8*c8+x9*c9+x10*c10+x11*c11+x12*c12+x13*c13+x14*c14+x15*c15+x16*c16;
x1+x4+x5+x11>=1;
x1+x2+x11+x15+x16>=1;
x1+x2+x3+x15+x16>=1;
x1+x4+x5+x11+x16>=1;
x2+x3+x6+x12+x15+x16>=1;
x1+x4+x8+x11>=1;
x8+x4+x5+x9+x11>=1;
x2+x6+x5+x16>=1;
x6+x9+x5+x10+x14>=1;
x6+x7+x10+x12+x14>=1;
x2+x3+x5+x6+x7+x12+x15>=1;
x8+x4+x13>=1;
x8+x9+x5+x13>=1;
x9+x14+x5+x10+x13>=1;
x7+x14+x9+x10>=1;
x6+x7+x10+x12>=1;
x9+x8+x13>=1;
x8+x9+x10+x13>=1;
x7+x9+x10>=1;
x2+x4+x3+x6+x7+x12+x15>=1;
c1=@if(x#gt#600,(4000*0.15*a1-2400000*0.15)/100000,0)+5;
c2=@if(x#gt#600,(4000*0.15*a2-2400000*0.15)/100000,0)+5;
c3=@if(x#gt#600,(4000*0.15*a3-400000*0.15)/100000,0)+5;
c4=@if(x#gt#600,(4000*0.15*a4-400000*0.15)/100000,0)+5;
c5=@if(x#gt#600,(4000*0.15*a5-2400000*0.15)/100000,0)+5;
c6=@if(x#gt#600,(4000*0.15*a6-2400000*0.15)/100000,0)+5;
c7=@if(x#gt#600,(4000*0.15*a7-2400000*0.15)/100000,0)+5;
c8=@if(x#gt#600,(4000*0.1*a8-2400000*0.1)/100000,0)+3.5;
c9=@if(x#gt#600,(4000*0.1*a9-2400000*0.1)/100000,0)+3.5;
c10=@if(x#gt#600,(4000*0.1*a10-2400000*0.1)/100000,0)+3.5;
c11=@if(x#gt#600,(4000*0.1*a11-2400000*0.1)/100000,0)+3.5;
c12=@if(x#gt#600,(4000*0.1*a12-2400000*0.1)/100000,0)+3.5;
c13=@if(x#gt#600,(4000*0.05*a13-2400000*0.05)/100000,0)+2;
c14=@if(x#gt#600,(4000*0.05*a14-2400000*0.05)/100000,0)+2;
c15=@if(x#gt#600,(4000*0.05*a15-2400000*0.05)/100000,0)+2;
c16=@if(x#gt#600,(4000*0.05*a16-2400000*0.05)/100000,0)+2;
x1*a1+x4*a4+x5*a5+x11*a11=120;
x1*a1+x2*a2+x11*a11+x15*a15+x16*a16=180;
x1*a1+x2*a2+x3*a3+x15*a15+x16*a16=230;
x1*a1+x4*a4+x5*a5+x11*a11+x16*a16=120;
x2*a2+x3*a3+x6*a6+x12*a12+x15*a15+x16*a16=150;
x1*a1+x4*a4+x8*a8+x11*a11=180;
x8*a8+x4*a4+x5*a5+x9*a9+x11*a11=180;
x2*a2+x6*a6+x5*a5+x16*a16=150;
x6*a6+x9*a9+x5*a5+x10*a10+x14*a14=100;
x6*a6+x7*a7+x10*a10+x12*a12+x14*a14=160;
x2*a2+x3*a3+x5*a5+x6*a6+x7*a7+x12*a12+x15*a15=180;
x8*a8+x4*a4+x13*a13=240;
x8*a8+x9*a9+x5*a5+x13*a13=210;
x9*a9+x14*a14+x5*a5+x10*a10+x13*a13=220;
x7*a7+x14*a14+x9*a9+x10*a10=280;
x6*a6+x7*a7+x10*a10+x12*a12=260;
x9*a9+x8*a8+x13*a13=320;
x8*a8+x9*a9+x10*a10+x13*a13=380;
x7*a7+x9*a9+x10*a10=360;
x2*a2+x4*a4+x3*a3+x6*a6+x7*a7+x12*a12+x15*a15=300;
@bin(x1);
@bin(x2);
@bin(x3);
@bin(x4);
@bin(x5);
@bin(x6);
@bin(x7);
@bin(x8);
@bin(x9);
@bin(x10);
@bin(x11);
@bin(x12);
@bin(x13);
@bin(x14);
@bin(x15);
@bin(x16);
我的LINGO显示没有可行解貌似