public static void main(String[] args) {

    int num = 29;
    boolean flag = false;
    for(int i = 2; i <= num/2; ++i)
    {
        // condition for nonprime number
        if(num % i == 0)
        {
            flag = true;
            break;
        }
    }

    if (!flag)
        System.out.println(num + " is a prime number.");
    else
        System.out.println(num + " is not a prime number.");
}