def main():
# based on Fermat's Little Theorem
r = 0
for p in take_while(primes(), lambda p: p < 1000):
if p == 2 or p == 5: continue
rp = multiplicative_order(10, p)
if rp > r:
r = rp
q = p
return q
def main():
return sum(take_while(primes(), lambda p: p < 2000000))
