U.S. Marine Corps Gunnery Sgt. Michael K. Wymer, a military policeman, picks up trash during a community service project March 28, 2014, at Ocheon Stream in Pohang, South Korea, as part of exercise Ssang Yong 2014. Ssang Yong is a combined U.S.-South Korean combat readiness and joint/combined interoperability exercise designed to advance South Korean command and control capabilities through amphibious operations.