import java.util.Scanner;

class Main {

// 判断一个数是否是质数

public static boolean isPrime(int num) {
    if (num < 2) {
        return false;
    }
    for (int i = 2; i * i <= num; i++) {
        if (num % i == 0) {
            return false;
        }
    }
    return true;
}

// 找到第 k 个质数

public static int findKthPrime(int k) {
    int count = 0;
    int num = 2;
    while (true) {
        if (isPrime(num)) {
            count++;
            if (count == k) {
                return num;
            }
        }
        num++;
    }
}

public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    while (scanner.hasNextInt()) {
        int k = scanner.nextInt();
        System.out.println(findKthPrime(k));
    }
    scanner.close();
}

}