#!/usr/bin/perl

use strict;
use warnings;

my %index;
my @data = qw/1 2 3 4 3 4 5 1 11 11 11 11 11 3/;
my $filename;

for (@data) {
	if ($index{$_}) {
		$filename =  $_ . $index{$_};
		$index{$_}++;
	}
	else {
		$filename = $_;
		$index{$_} = 'a';
	}
	print "Your filename is $filename.\n";
}