Dunder Mifflin Co. began the year with $400,000 in assets and $250,000 in liabilities. During the year, Dunder Mifflin recorded $50,000 in sales, $10,000 in expenses, and did not pay any dividends. If the company had a $100,000 increase in total assets and no change in liabilities, what was the amount of common stock that was issued during the year?