Nick's dad wanted to measure the length of his backyard and asked Nick to do this with his footsteps. Since it was winter, they
were able to count their footprints in the snow starting from the end of the backyard moving in the same direction towards the front. In some places, Nick and his dad's footprints coincided. Eventually, they counted 67 footprints, including their first step. What is the length of the backyard in meters, if the Nick's footstep is 51 cm long and his dad's is 68 cm long?
