def answer():
primes.append_primes_until(9999)
prime_list = [x for x in primes.primes if x > 1000]
prime_permutations = defaultdict(lambda:[])
for i in prime_list: prime_permutations[''.join(sorted(str(i)))] += [i]
for p in prime_permutations:
prime_group = defaultdict(lambda:[])
pp = prime_permutations[p]
for n in range(len(pp)-1):
for m in range(n+1, len(pp)):
prime_group[abs(pp[m]-pp[n])] += [pp[n], pp[m]]
for g in prime_group:
pg = prime_group[g]
if len(pg) >= 3:
for a in range(0,len(pg)-2):
for b in range(a+1, len(pg)-1):
for c in range(b+1, len(pg)):
if (pg[a] - pg[b]) == (pg[b] - pg[c]):
return '{0}{1}{2}'.format(pg[a], pg[b], pg[c])
def answer():
primes.append_primes_until(2000000)
return sum(x for x in primes.primes if x < 2000000)
