import java.util.*;

// This program solves the problems on slide 7 given in lecture on 
// Monday, July 19, 2010.
public class PrintNumbers {
    public static void main(String[] args) {
        printPrimes(50);
    }
    
    // This method prints all primes up to a given max.
    public static void printPrimes(int max) {
        System.out.print("[2");
        
        for (int i = 3; i <= max; i++) {
            if (countFactors(i) == 2) {
                System.out.print(" " + i);
            }
        }
        
        System.out.print("]");
    }
    
    // This method returns the number of factors a given number has.
    public static int countFactors(int num) {
        int count = 0;
        
        for (int i = 1; i <= num; i++) {
            if (num % i == 0) {
                count++;
            }
        }
        
        return count;
    }
}