//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.
static void Main()
{
int max = 0;
int[] num=new int[10000];
num[0]=1;
num[1]=2;
int sum = 2;
for(int i=0;max<4000000;i++)
{
num[i + 2] = num[i] + num[i + 1];
max = num[i + 2];
if (max % 2 == 0)
{
sum = sum + num[i + 2];
if (max > 4000000)
{
sum = sum - num[i + 2];
}
}
}
Console.WriteLine(sum);
}