/**
 * \file
 * \brief [Problem 7](https://projecteuler.net/problem=7) solution.
 * @see Faster version problem_7/sol.c
 */
#include <stdio.h>

/** Main function
 * @return 0 on exit
 */
int main()
{
    int n;
    scanf("%d", &n);
    int number_of_prime = 0;
    for (int i = 2;; i++)
    {
        int divisors = 0;
        for (int j = 1; j <= i; j++)
        {
            if (i % j == 0)
            {
                divisors++;
            }
        }
        if (divisors == 2)
        {
            number_of_prime++;
            if (number_of_prime == n)
            {
                printf("%d", i);
                break;
            }
        }
    }

    return 0;
}