from acmlib import primes_below print sum(primes_below(2000000))
from acmlib import primes_below, is_prime
def check(n):
# if not is_prime(n):
# return False
s = str(n)
for i in xrange(1, len(s)):
pre = int(s[i:])
suf = int(s[:-i])
if not is_prime(pre) or not is_prime(suf):
return False
return True
result = 0
for p in primes_below(1000000)[4:]:
if check(p):
result += p
print result