KöMaL 2009 K230

The traditional way of numbering houses in a street uses odd numbers on one side and even numbers on the other side. Numberless Street is bounded by identical plots of land on both sides. The odd side is fully developed, there is one house on each plot of land. On the even side, there are a few consecutive plots that have no houses on them yet, but there are two houses on the first plot. The owners decided to use number plates of the same design in the whole street. The number plates they bought are sold for 50 forints a digit (HUF, Hungarian currency). They spent 4250 forints altogether. The numbers for the odd side cost 550 forints more than the numbers for the even side. The owner of the first house on the odd side considered 1 an unlucky number, so they started the numbering by 3. On the even side, the two houses on the first plot got the numbers 2 and 4. They did not buy number plates for the houses that would be built on the vacant plots, but they did take them into consideration in numbering: they did not give their numbers to other buildings. What is the largest number on the odd side and how many vacant plots are there on the even side?