sum of even Fibonacci numbers less than 4 million

/*
 * bhatt.umang7@gmail.com
 */

/*
 * Each new term in the Fibonacci sequence is generated by adding the previous 
 * two terms. By starting with 1 and 2, the first 10 terms will be:
 *
 * 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
 *
 * By considering the terms in the Fibonacci sequence whose values do not exceed four
 * million, find the sum of the even-valued terms.
 */

public class Problem2
{

    public static void main(String args[])
    {
        long ans = 0  ; 
        long sum = 0 ;

        long max = 4000000;
        long prev_prev = 0 ;

        long prev = 1 ;
    
        while (sum< max)
        {

            sum = prev_prev  + prev ;
            prev_prev = prev ; 
            prev = sum ;

            if (sum%2 == 0)
            {
                ans += sum ;
            }
        }

        System.out.println("Ans is "+ ans );
        // ans is 
    }
}