#!/usr/bin/perl -w
use warnings;

print "Please enter first DNA sequence\n";
$firstDna = <STDIN>;

$frstLength = length($firstDna);

print "Please enter second DNA sequence\n";
$secondDna = <STDIN>;

$scndLength = length($secondDna);

print "Please enter third DNA sequence\n";
$thirdDna = <STDIN>;

$trdLength = length($thirdDna);

print "Please enter fourth DNA sequence\n";
$fourthDna = <STDIN>;

$frthLength = length($fourthDna);

@array = sort($frstLength, $scndLength, $trdLength, $frthLength);

print "Your Dna sequence length is: @array";