http://www.perlmonks.org?node_id=11101105

Someone posted this challenge at work..
The country of Elbonia is standardizing its postal system to streamline its parcel service. All parcel boxes (many sizes available) now come with 10 preprinted rectangles on one side for stamps to be stuck into. Elbonia's stamp denominations are:
1c, 2c, 3c, 4c, 5c, 10c, 24c, 37c, 39c, 41c, 48c, 60c, 63c, 70c, 75c, 80c, 83c, 84c, 87c, $1, $3.85, $4.05, $4.60, $5, $14.40
Given an infinite supply of each denomination, what is the minimum postage amount that would REQUIRE 11 stamps and so not work with the streamlined service?

my$w={0=>1,1=>1,2=>2,3=>3,4=>4,5=>5,10=> 10,24=>24,37=>37,39=>39,41=>41,48=>48,60 =>60 ,63=> 63, 70=> 70,75 =>75 ,80=>80 ,83=> 83, 84=>84,87=>87, 100=> 100, 385=>385,405=>405 ,460=> 460 ,500=>500,1440=> 1440}; my@a =sort{$a<=>$b}keys %{$w}; for( 1..9){foreach my$c (keys %{$w} ){foreach my $v(@a) {my $n =$c+ $v;if(!exists$w-> {$n}) {$w ->{$n}=$w->{$c}. "+".$v ;}}} }my@r=sort{$a<=> $b}keys %{$w };my$h=pop@r; for my$i (0.. $h){if(exists $w->{$ i}){ print"$ i->". $w-> {$i}."\n" ;}### else{ print"!$i \n";} }### # ########## ##### #### # ############ ##### #### # ############## ##### #### # ################ ##### #### ################### ##### #### ############## ##### #### ## ## ######################################## ##### # ########### ############## ##### ########################################