import math
def main():
    n = int(input())
    a = [1]
    b = []
    for i in range(1000001, 100000001):
        flg = True
        for j in (2,math.sqrt(i)):
            if i % j == 0:
                flg = False
                break
        if flg:
            b.append(i)

    for i in range(len(b)):
        for j in range(1,10):
            a.append(b[i] * j)

    a.sort()
    print(a[n - 1])
main()