#!/usr/bin/perl -w 

use strict;

sub FindRoot;

my %Word=map {chomp;split /,/} <>;

for (keys %Word)
{
 print "Word: $_, etc: $Word{$_}\n";
};

my $Root=FindRoot("Longest",keys %Word);
my @Words=map {split} (values %Word);
my $Word=FindRoot("Shortest",@Words);

print "\n---\n$Root:$Word\n";
for (keys %Word)
{
 print "-",substr($_,length$Root),":";
 
 print "",substr($Word{$_},0,rindex($Word{$_},$Word)),"\n";
};

sub FindRoot
{
 my $Order=shift;
 my %Container;
 my $Min="xxxxxxxxxxxxxxx";
 print "Finding $Order\n";
 if ($Order eq "Shortest")
 {
  $Min="";
  $Min=((length $_)>(length $Min))?$_:$Min for (@_);
 } 
 else { $Min=((length $_)<(length $Min))?$_:$Min for (@_); };
 for my $Word (@_)
 {
  $Container{substr lc $Word,0,$_}++ for(2..length $Min);
 };
 my $Root="";
 $Min=0;
 my @List=sort keys %Container;
 @List=reverse@List if ($Order eq "Longest");
 print "List: @List\n";
 for (@List)
 {
  if ($Container{$_}>$Min)
  {
   $Root=$_;
   $Min=$Container{$_};
  };
 };
 return $Root;
};