primes.py

from sys import argv
from math import sqrt

maxval = int(argv.pop())

x = [ True ] * maxval
x[0] = False
for n in xrange(1, int(sqrt(maxval + 1)), 2):
  if x[n - 1]:
	m = n ** 2
	increment = 2 * n
	while m <= maxval:
	  x[m - 1] = False
	  m += increment

primes = [ n for n in xrange(1, maxval + 1, 2) if x[n - 1] ]
print sum(primes) + 2