What have you tried?

You could:

use strict;
use warnings;

my @array = (1, 2, 3, 4, -1, -2, -3, 11, 12, 13);
my $max = 0;
my $sum;

    ($a = ($_ > 0 ... $b + 1 != $_)),
    ($a and $a == 1 and $sum = 0),
    ($a and $a !~ /E0/ and $sum += $b = $_),
    ($a and $sum > $max and $max = $sum)
    for @array;

print $max;
[download]

which prints 36, but your teacher may not like that.