Astrid is in charge of building a new fleet of ships. Each ship requires 40 4040 tons of wood, and accommodates 300 300300 sailors. She receives a delivery of 4 44 tons of wood each day. The deliveries can continue for 100 100100 days at most, afterwards the weather is too bad to allow them. Overall, she wants to build enough ships to accommodate at least 2100 21002100 sailors. What is the number of ships Astrid can build, assuming she receives the maximum possible amount of wood?