def sub1():
a, b = set(), set()
for i in range(3, 20):
a = set(factors(i-1))
b = set(factors(i))
if len(a & b) == 0 and len(a) == 2 and len(b) == 2:
print "answer", i-1, i
def sub2():
a, b, c = set(), set(), set()
for i in range(4, 700):
a = set(factors(i-2))
b = set(factors(i-1))
c = set(factors(i))
if len(a & b & c) == 0 and len(a) == 3 and len(b) == 3 and len(c) == 3:
print "answer", i-2, i-1, i
def main():
a, b, c, d = set(), set(), set(), set()
for i in range(134000, 140000): # answer is 134043
a = set(factors(i-3))
b = set(factors(i-2))
c = set(factors(i-1))
d = set(factors(i))
if len(a & b & c & d) == 0 and len(a) == 4 and len(b) == 4 \
and len(c) == 4 and len(d) == 4:
print i-3
break