Basic while loop expression.

Write a while loop that repeats while user$\_$num $>=1.$ In each loop iteration, first divide user$\_$num by $2,$ then print user$\_$num.

Sample output with input: $20$

$10\mathrm{.}0$

$5\mathrm{.}0$

$2\mathrm{.}5$

$1\mathrm{.}25$

$0\mathrm{.}625$