my @array = (1,5,6,7,8,55,63,77,89,103,104,105,106,200,215,554);
my @runs = @array[
    grep {
        $array[$_+1] == 1+$array[$_] .. $array[$_+1] != 1+$array[$_]
    } 0..$#array
];
print "@runs",$/;