Finding the sum of even valued terms in a fibonacci sequence whose values do not exceed four million

Project Euler Problem 2

/*

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.

*/

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ConsoleApplication1

{

class Program

{

static void Main(string[] args)

{

int sum=0,f=1, prev1=1, prev2=0;

while( f<4000000)

{

f = prev1 + prev2;

Console.Write(f + ", ");

prev2 = prev1;

prev1 = f;

if (f % 2 == 0)

{

sum = sum + f;

}

}

Console.WriteLine("Sum of all even numbers in a fibonacci sequence where value is less than 4 million is " + sum);

}

}

}