#!/usr/bin/perl
use v5.14;

my $result = 0;


sub fib
{
 my  @frame = @_;

 @frame[0] = @frame[0] + @frame[1];
 @frame[1] = @frame[2];
 @frame[3] = @frame[2];
 
 count($frame[0]);

 return fib(@frame) unless($frame[0] >= 4000000);
}

sub count
{
        my $increment = @_;
        if(($increment  % 2) == 0)
        {
                $result = $result + $increment;
        }
}

fib(1,2,3);
print $result;