How to find the sum of all the even-valued terms in the Fibonacci sequence which do not exceed four million?

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, ...

Find the sum of all the even-valued terms in the sequence which do not exceed four million.

Note: Solve yourself before going directly to the solution

Solution:
Language: C#
int term1 = 1, term2 = 2;
int sum = 0;

while (term2 <= 4000000)

{

if ((term2 % 2) == 0)

      {

       sum += term2;

      }            

      // Switch values

      term1 = term1 + term2;

      term2 = term1 - term2;

      term1 = term1 - term2;

      // calculate next value by adding previous two terms

      term2 = term1 + term2;

}