A mountaineer uses a global positioning system receiver to measure his displacement from base camp to the top of Mount McKinley. In terms of horizontal coordinates x and y, the base camp is at x = 0, y = 0, and the base of Mount McKinley is at x = 1600 m, y = 4200 m. If the altitude of Mount McKinley is 6200 m and the base camp is at 4027 m, what is the displacement in going from base camp to the top?