#!/usr/bin/perl -w

use strict;

@ARGV == 1 && $ARGV[0] >= 0
	or die "syntax: $0 lines\n";

my @buf;
my $n = shift;
my $line;

while ($n > 0 && defined ($line = <STDIN>)) {
	push @buf, $line;
	--$n;
}
if ($n == 0) {
	$n = @buf;
	while (defined ($line = <STDIN>)) {
		$buf[$n] = $line;
		++$n;
		$n = 0 if $n == @buf;
		print $buf[$n];
	}
}