Ali Disk Company operates a computer disk manufacturing plant. Direct materials are added at the end of the process. The following data were presented for August:

Work in process, beginning inventory$100,000$ units$$ Transferred$-$in costs $(100\%$ complete$)$ Direct materials $(0\%$ complete$)$ Conversion costs $(90\%$ complete$)$Transferred in during current period$300,000$ unitsCompleted and transferred out$350,000$ units$$Work in process, ending inventory$$ Transferred$-$in costs $(100\%$ complete$)$ Direct materials $(0\%$ complete$)$ Conversion costs $(65\%$ complete$)$

How many units must be accounted for during the period, assuming a FIFO cost flow?