A bird is released from point A on an island, 5 miles from B, the nearest point on a straight shoreline. The bird's nesting place is 13 miles across the water to from point A to point D. Suppose the bird flies to a point C on the shoreline and then flies along the shoreline to its nesting area D. If the bird expends 14 calories of energy per mile over water and 10 over land, how far should C be from B so the bird expends exactly 170 calories of energy?