how can i calculate the gross profit?

Swifty Company sells one product. Presented below is information for January for Swifty Company. Swifty uses the FIFO cost flow assumption. All purchases and sales are on account. entry" for the account titles and enter 0 for the amounts. Credit account titles are automatically indented when amount is entered. Do not indent manually.) Compute gross profit using the periodic system. Grossprofit $ eTextbook and Media