size = 2000000
numbers = [1] * size
numbers[:2] = [0] * 2
end = int(math.sqrt(size))
for index, is_primer in enumerate(numbers[:end]):
if is_primer:
cursor = index + index
while cursor < size:
numbers[cursor] = 0
cursor += index
print sum(
index
for index, is_primer in enumerate(numbers)
if is_primer
)