# 1533776805
import euler
n = 144
while True:
h = n * (2 * n - 1)
if euler.is_pentagonal(h) and euler.is_triangular(h):
print h
break
n += 1
def compute():
n = 144
while not (is_triangular(n * (2 * n - 1)) and is_pentagonal(n * (2 * n - 1))):
n += 1
return n * (2 * n - 1)