#nth prime number
from math import sqrt
def NthPrime(n) :
    count = 0
    MAX=1000
    for i in range(2, MAX + 1) :
        check = 0
        for j in range(2, int(sqrt(i)) + 1) :
            if i % j == 0 :
                check = 1
                break

        if check == 0 :
            count += 1

        if count == n :
            return i
            break
n=int(input())
print(NthPrime(n))