sub count2 {
    my $s=shift;
    my %saw;
    my %count = map {
        map {
            $saw{$_}++ ? () : 
              $_ => scalar(()= $s =~ /$_/g);
        } do { pos=$_; $s =~ /(.{2,}).*\1/g };
    } 0..length($s)-1;
    \%count;
}