[Help-glpk] Counting solutions rather than optimizing solutions

[Salim Fadhley]

For an experimental project my objective is to count the number of solutions
andnot optimize for a particular constraint. The puzzle is a pretty basic one 
for
now:

var a1 >=0;  /* 200 */
var b1 >=0;  /* 100 */
var c1 >=0;  /* 50 */
var d1 >=0;  /* 20 */
var e1 >=0;  /* 10 */
var f1 >=0;  /* 5 */
var g1 >=0;  /* 2 */
var h1 >=0;  /* 1 */

s.t. Make: a1 * 200 + b1*100 + c1 * 50 + d1 * 20 + e1 * 10 + f1 * 5 + g1 * 2 +
h1 <= 1000

As far as this puzzle is concerned no valid solution of the above is more
valid than any other, I just need a way to enumerate how many of them exist. Is
there an objective function that will just give me the count of solutions?