#original seq: 

accgttac 

#required output:

acc         #first substring

ccg

cgt

tta

tac         #fifth substring


##</code><code>##


#!/usr/local/bin/perl

use strict;

use warnings; 

for(<DATA>){

              print substr ($_,0,3),"\n" ; 

              } 

__DATA__

accgttac


##</code><code>##

 
run Start -> Program Files -> Strawberry Perl -> CPAN Client

##</code><code>##

           CPAN> install BioPerl