An accumulation conveyor is to be provided at a workstation. When the conveyor is full, parts are diverted to another area for processing. Parts arrive at a Poisson rate of 2 per minute. The time required to process a part at the workstation is exponentially distributed with a mean of 18 seconds per part. It is desired to provide an accumulation line of sufficient length so that less than 1% of the arriving parts will be diverted to another area for processing. What is the minimum number of waiting spaces that will satisfy the objective?