my $min_col_2 = 1_000_000; # Something large enough
my $max_col_2 = 0; # Something small enough

my $min_col_3 = 1_000_000; # Something large enough
my $max_col_3 = 0; # Something small enough

while(<>){
    if(/^ZZ/){
        my @array = split;
        if($min_col_2 > $array[1]){
            $min_col_2 = $array[1];
        }
        if($max_col_2 < $array[1]){
            $max_col_2 = $array[1];
        }
        # Snip
    }
}