#!/bin/perl

my @months=qw/"" jan feb mar apr may jun jul aug sep oct nov dec/; 
open(DATAS,"<","sales.txt") ; 
my (%report,$cust,$value,$date); 

for (@months) 
{ 
print "$_","\t"; 
} 
print "\n"; 
while (<DATAS>) 

{ chomp; 
if (/^[A-Z]/) { 
	$cust = $_; 
	@{$report{$cust}} = map { 0 } @months; 
	next; 
} 
($date,$value) = split ' ', $_; 
my ($mon,$year) = split '/',$date; 
$report{$cust}[$mon]=$value; 

}

foreach my $keys (keys %report) 
{
print $keys,"\t"; 
for (0..12) 
{ print $report{$keys}[$_],"\t"; 
} 
print "\n"; 
}  
print "\n";