What is the direct material inventory balance at the end of march?

Sales are 40% cash and 60% on account, and 60% of credit sales are collected in the month of the sale. In the month after the sale, 40% of credit sales are collected. It takes 4kg of direct materials to produce a finished unit, and direct materials cost $5 per kg. All direct materials purchases are on account, and are paid as follows: 40% in the month of the purchase and 60% the following month. Ending direct materials inventory for each month is 40% of the next month's production needs. January's beginning materials inventory is 990kg. Suppose that both accounts receivable and accounts payable are zero at the beginning of January