--- /dev/null
+#!/usr/bin/perl -w
+
+use strict;
+
+my $rounds;
+($rounds, $_) = @ARGV;
+
+while ($rounds--) {
+ my ($cur) = /\A(.)/;
+ do {
+ $cur--;
+ $cur = 9 if $cur == 0;
+ } while (/\A.{1,3}$cur/);
+
+ s/\A(.)(...)(.*)$cur(.*)\z/$3$cur$2$4$1/;
+ print $_, "\n";
+}
+
+s/\A(.*)1(.*)\z/Result is $2$1\n/;
+print;