def primes(n):
    is_prime = [True] * (n + 1)
    is_prime[0] = False
    is_prime[1] = False
    for i in range(2, 10 ** 5 + 1):
        is_prime[i] = False
    for i in range(2, int(n**0.5) + 1):
        if not is_prime[i]:
            continue
        for j in range(i * 2, n + 1, i):
            is_prime[j] = False
    return [i for i in range(n + 1) if is_prime[i]]


n = int(input())
if n == 1:
    print(1)
else:
    print(primes(2 * 10 ** 5)[n - 2])