#!/usr/bin/perl -w
use strict;
my @domains1=('PF05.3','PF11001.3','PF00389.24','PF10417.3');
my @domains2=('PF01','PF02','PF11001.3','PF00389');
my @domains3=('PF00389.24','PF05.3','PF01','PF00389');
my %h;
my $element;
open(INPUTDOMAINLIST,'<domainlist') or die "cannot open 

'domainlist'becuase:$!";
chomp (my @list=<INPUTDOMAINLIST>);
foreach my $domain(@list){
foreach  $element(@domains1){
$element=$_;
if($element=~/(\Q$domain\E/)){
my $i=indexarray("$element",@domains1);
if($i==0){
$h{$element}=$domains1[1];
}
elsif($i!=0 && $i<scalar(@domains1)-1){
$h{$element}=$domains1[$i-1];
$h{$element}=$domains1[$i+1];
}

elsif($i==scalar(@domains1)-1){
$h{$element}=$domains1[$i-1];
}
}}
print " $h{$element}";



sub indexarray{
my $s=shift;
 $_ eq $s && return @_ while $_=pop;
 -1;}