A company reported total stockholders' equity of $340,000 on its balance sheet dated December 31, 2015. During the year ended December 31, 2016, the company reported net income of $40,000, declared and paid a cash dividend of $8,000, declared and distributed a 10% stock dividend with a $10,000 total market value, purchased treasury stock costing $12,000, and issued additional common stock for $60,000. What is total stockholders' equity as of December 31, 2016?