my $str="catgatgttttccctatgggatttttgaa";
my $tree=create_tree($str);

my $filename7 = "C:\\MB\\Cp\\mississippi_out_7.txt";
open(MY7, ">>$filename7") or die "Unable to open $filename7: $!\n";

my $orig = select(MY7);
print_tree($tree);
select($orig);