import sys
readline = sys.stdin.readline


def prsh(N):
    prime = [2]
    for L in range(3,N):
        for p in prime:
            if not L % p:
                break
            if p > L**(1/2):
                prime.append(L)
                break
    return prime

limit = 100200
prime = [i for i in prsh(limit) if i > 100000]

ss = set([0, 1])
for p in prime:
    for p2 in prime:
        ss.add(p*p2)
ss = list(ss)
ss.sort()
print(ss[int(readline())])