Assume that the work$-$content time for each unit of product is $8\mathrm{.}5$ hours. The

frequency of operation failure per robot is $0\mathrm{.}01\%.$ When a failure occurs, the

corresponding robot's downtime is $2\mathrm{.}5$ hours. If the efficiency of the production line

is to be $97\%,$ how many robots must be employed in this automatic production line?