Even Fibonacci Sum

You are given an integer n. Your task is to compute the sum of all even Fibonacci numbers that do not exceed n. The Fibonacci sequence is defined as:

\(F_0 = 0,\; F_1 = 1\) and \(F_{k+2} = F_{k+1} + F_k\) for \(k \ge 0\).

For example, when \(n = 34\), the Fibonacci sequence terms that do not exceed 34 are:

• 0 (even)
• 1
• 1
• 2 (even)
• 3
• 5
• 8 (even)
• 13
• 21
• 34 (even)

The sum of the even-valued terms is \(0+2+8+34 = 44\). Your solution should read the input from standard input and print the result to standard output.

inputFormat

The input consists of a single line containing one integer n (\(0 \le n \le 4\,000\,000\)).

outputFormat

Output a single integer, which is the sum of the even Fibonacci numbers that do not exceed n.

10

10