Department B had 3,000 units in Work in Process that were 25% completed at the beginning of the period at a cost of $12,500, 13,700 units of direct materials were added during the period at a cost of $28,700, 15,000 units were completed during the period, and 1,700 units were 95% completed at the end of the period. All materials are added at the beginning of the process. Direct labor was $32,450 and factory overhead was $18,710. The number of equivalent units of production for the period for materials, if the first-in, first-out method is used to cost inventories, was