c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my @ra = (1, 1, 1, 2, 3, 4, 4, 4, 5, 6, 1, 1, 1);
 dd \@ra;
 ;;
 my $one;
 $one = pop @ra while $ra[-1] == 1;
 push @ra, $one if defined $one;
 dd \@ra;
"
[1, 1, 1 .. 4, 4, 4, 5, 6, 1, 1, 1]

[1, 1, 1 .. 4, 4, 4, 5, 6, 1]

##</code><code>##

c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my @ra = (1, 1, 1, 2, 3, 4, 4, 4, 5, 6, 1, 1, 1);
 dd \@ra;
 ;;
 my $highest;
 for my $i (reverse 0 .. $#ra) {
   last if $ra[$i] != 1;
   $highest = $i;
   }
 $#ra = $highest if defined $highest;
 dd \@ra;
"
[1, 1, 1 .. 4, 4, 4, 5, 6, 1, 1, 1]

[1, 1, 1 .. 4, 4, 4, 5, 6, 1]