Even Fibonacci numbers | Project Euler | Problem #2

URL to the problem page: https://projecteuler.net/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.

#include <iostream>

using namespace std;

int main()

{

    long long sum = 0, f1 = 1, f2 = 1, number = f1 + f2;

    while (number <= 4000000) {

        number = f1 + f2;

        f1 = f2;

        f2 = number;

        if (number % 2 == 0) {

            sum += number;

        }

    }

    cout << "Sum of the even-valued Fibonacci numbers below 4.000.000 is  =  " << sum << endl;

    return 0;

}

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