# this heuristic seems to be faulty
        my $min_mm = scalar( uniq(@colbp) ) - 1;

##</code><code>##

        my %chars;
        foreach my $site ( @{$tfbs} ) {
            my $bp = substr($site,$pos,1);
            $chars{$bp} = 1;

        }
        
       # this heuristic seems to be faulty
        my $min_mm = keys %chars - 1;
        push @mincol, $min_mm;


##</code><code>##

# is: 
00100000302011000000100
# should be:
00100000301011000000100