The profile of the cables on a suspension bridge may be modeled by a parabola. The central span of the bridge is 1240 m long and 135 m high. The parabola y equals 0.00035 x squared gives a good fit to the shape of the​ cables, where StartAbsoluteValue x EndAbsoluteValue less than or equals 620 ​, and x and y are measured in meters. Approximate the length of the cables that stretch between the tops of the two towers.