public class eratosthenes {

    public static void main(String a[]) {

        // step 0: define max
        int max = 200;

        // step 1: set up an array of max booleans
        boolean sieve[] = new boolean[max];

        // step 2: set all booleans (from index 2 to max -1) to false (i.e. not crossed)
        int i;
        for (i = 2; i < max; i++) {
            sieve[i] = false;
        }

        // step 3: run the algortihm of the sieve of Eratosthenes
        //         (see http://en.wikipedia.org/wiki/Sieve_of_eratosthenes )
        for (i = 2; i < max; i++) {
            // cross every i-th element starting with the (i+i)-th element
            // (no need to go on if the i-th element is already crossed
            if (sieve[i] == false) {
                int m = i + i;
                while (m < max) {
                    sieve[m] = true;
                    m += i;
                }
            }
        }

        // step 4: print out all i for which sieve[i] is still false
        for (i = 2; i < max; i++) {
            if (sieve[i] == false) {
                System.out.println(i);
            }
        }      
       
    }

}