import math
def is_prime(n):
    if n == 1: return False
    for k in range(2, int(math.sqrt(n)) + 1):
        if n % k == 0:
            return False
    return True

prime = []
for i in range(10**5, 10**5+500):
    if is_prime(i):
        prime.append(i)
suteki = set()
for i in prime:
    for g in prime:
        suteki.add(i*g)

suteki = list(suteki)
suteki.sort()

n = int(input())
if n == 1:
    print(1)
else:
    print(suteki[n-2])