#!/usr/bin/perl

$fib1 = 1;
$fib2 = 1;

$sum = 0;

while ($fib2 < 1000000) {
  $old = $fib2;
  $fib2 = $fib1 + $fib2;
  $fib1 = $old;
  if ($fib2 % 2 == 0) {
    $sum += $fib2;
  }
}

print $sum . "\n";