问我如何在AMPL中得到一个整数解？

EN

set PHONE;
set COMPONENTS;

param price {PHONE} >= 0;
param cost {PHONE} >= 0;
param maxComponents {COMPONENTS} >= 0;
param ordered {PHONE} >= 0;
param matrix {COMPONENTS, PHONE}; #The amount of components needed to make a particular phone.

var x {PHONE} >= 0; # Number of manufactured telephones.

maximize profit: sum {i in PHONE} ( ordered[i] * price[i] - x[i] * cost[i] );

subject to min_manufacture {i in PHONE}:
    x[i] >= ordered[i]; # We must produce a minimum of what is ordered

subject to component {i in COMPONENTS}:
    sum {j in PHONE} matrix[i,j] * x[j] <= maxComponents[i]; # The number of components used must not exceed the maximum.

subject to min_quantity {i in COMPONENTS, l in PHONE}:
    sum {j in PHONE} matrix[i,j] * x[j] >= matrix[i,l]; # Minimum quantity used per component if we manufacture at least one telephone. For example, a triple phone requires at least 2 of the five components.

set PHONE := 1 2 3 4 5;
set COMPONENTS:= 1 2 3 4 5 6 7;

param price := 
1 450
2 120
3 500
4 390
5 100;

param cost :=
1 370
2 90
3 400
4 320
5 70;

param maxComponents :=
1 28
2 20
3 8
4 30
5 47
6 27
7 15;

param ordered :=
1 3
2 5
3 5
4 0
5 10;

param matrix: 1 2   3   4   5 :=
    1   1   1   0   0   0
    2   1   1   0   0   0   
    3   1   0   0   0   0
    4   1   0   1   1   0
    5   0   0   2   1   1
    6   0   0   2   1   0
    7   0   0   1   1   0;

model phone.mod;
data phone.dat;
option presolve 0;
option solver cplex;
solve;
display profit,  x;
display {i in COMPONENTS, j in PHONE} matrix[i,j] * x[j];