A group of U.S. Airmen and Army members from the U.S. Army 361st Civil Affairs Brigade and the U.S. Air Force 52nd Fighter Wing form up before the first day of the International Four Days Marches Nijmegen in Nijmegen, Netherlands, July 15, 2014. The 98th International Four Days Marches Nijmegen has grown into the largest multi-day walking event in the world. (U.S. Air Force photo by Senior Airman Gustavo Castillo/Released)