+#!/usr/bin/perl
+
+use v5.30;
+use strict;
+
+chomp(my $line = <>);
+my @l = map { ord } split //, $line;
+push @l, 17, 31, 73, 47, 23;
+
+my $pos = 0;
+my $skip = 0;
+# my @nodes = (0 .. 4);
+my @nodes = (0 .. 255);
+my $n = @nodes;
+
+for (1 .. 64) {
+for my $i (@l) {
+ my $end = $pos + $i;
+ my @to_rev;
+ say "pos=$pos skip $skip i=$i ", join(',', @nodes);
+ if ($end > $n) {
+ push @to_rev, splice @nodes, $pos;
+ push @to_rev, splice @nodes, 0, $end - $n;
+ @to_rev = reverse @to_rev;
+ say "to_rev = ", join(',', @to_rev);
+ unshift @nodes, splice @to_rev, @to_rev-($end-$n);
+ push @nodes, @to_rev;
+ } else {
+ push @to_rev, splice @nodes, $pos, $i;
+ splice @nodes, $pos, 0, reverse @to_rev;
+ }
+ $pos += $i + $skip++;
+ $pos -= $n while $pos >= $n;
+}
+}
+
+my $hash = '';
+while (my @s = splice (@nodes, 0, 16)) {
+ my $x = 0;
+ $x ^= $_ for @s;
+ $hash .= sprintf("%02x", $x);
+}
+say $hash;