class PrimesUsingMethods {
    /**
     * Checks whether its parameter is a prime or not.
     * @param n a positive integer
     * @return true if n is a prime, false otherwise
     */
    static boolean isPrime(int n) {
        for (int d = 2; d < n; d++)
            if (n % d == 0)
                return false;
        return true;
    }

    /**
     * Prints all primes <= maxN, 10 primes per line.
     * @param maxN an integer
     */
    static void printPrimesUpTo(int maxN) {
        int count = 0;
        System.out.println("Primes Table\n============");
        for (int n = 2; n <= maxN; n++) {
            if (isPrime(n)) {
                System.out.printf("%5d", n);
                count++;
                if (count == 10) {
                    System.out.println();
                    count = 0;
                }
            }
        }
        if (count < 10)
            System.out.println();
    }

    /*
     * This program gets an integer n from the command line
     * argument then prints all primes <= n.
     */
    public static void main(String[] args) {
        printPrimesUpTo(Integer.parseInt(args[0]));
    }
}