# sum of primes less than n
# sieve of eratosthenes
from time import time
def sumPrimes(n):
i, p, s, m = 0, 3, 2, n // 2
sieve = [True] * m
while p <= n:
if sieve[i]:
s += p
for j in range((p*p-3)/2, m, p):
sieve[j] = False
i, p = i+1, p+2
return s
start = time()
print sumPrimes(2000000)
print int(round(1000 * (time() - start))), "milliseconds"