A manufacturing company has a small production line dedicated to the production of a particular product. The line has four stations in serial. Inputs arrive at station 1 and the output from station 1 becomes the input to station 2. The output from station 2 is the input to station 3 and so on. The output from station 4 is the finished product. Station 1 can process 2,700 units per month, station 2 can process 2,500/month, station 3 can process 2,300/month, and station 4 2,100/month. What station sets the maximum possible output from this system? What is that maximum output number?