def isprime(n):
	if n == 0 or n == 1: return False
	for i in range(2, int(n**0.5 + 1)):
		if n%i == 0: return False
	return True

primes = []
for n in range(10**5):
	if isprime(n) == True:
		primes.append(n)

def rad(n):
	ans = 1
	for p in primes:
		if n%p == 0:
			ans *= p
		if p > n:
			break
	return ans

a = []

for n in range(1, 10**5+1):
	if n%1000 == 0: print n
	a.append([rad(n), n])

print (sorted(a))[10**4-1][1]