Kata

You need to count the number of prime numbers less than or equal to some natural n.

For example:

count_primes_less_than(34) = 11
count_primes_less_than(69) = 19
count_primes_less_than(420) = 81
count_primes_less_than(666) = 121

• In this kata all the tests will be with $1⩽n⩽10^{10}1\; \backslash leqslant\; n\; \backslash leqslant\; 10^\{10\}$
• Code length limited to 3000 characters to avoid hardcoding.

Good luck!