A state's environmental agency worries that a larger percentage of cars may be violating clean air standards. In the past, the percentage of cars that violate clean air standards has been 10%. The agency hopes to check a sample of vehicles in order to estimate that percentage with a margin of error of 1% and with 99% confidence.

How many cars should be sampled? Show your work! Formula(s), substitutions, answer! Round your z or t value to 3 decimal places.