[剑八]

沙漠探险日程安排问题
min (2*n1+1)*x1+(2*n2+1)*x2+x3
s,t (2*n1+1)-320*n1-640*n2<=0
(2*n2+1)*x2+x3-320*n2-320<=0
x1+x2+x3=480
x1>=0,x2>=0,x3>=0
n1,n2都为整数
请问怎么解