A builder makes staircases where each step is 28\,\text{cm}28cm28, start text, c, m, end text long and rises 18\,\text{cm}18cm18, start text, c, m, end text so people don't trip. Every staircase has a stringer — a diagonal support connecting all of the steps. A certain staircase will have 666 steps. What is the length \ellℓell of the stringer for this staircase? Round your answer to the nearest tenth of a centimeter. \text{cm}cmstart text, c, m, end text