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#!/usr/bin/php
<?php

$input = stream_get_contents(STDIN);
$data = explode("\n\n", $input);

$num_testcases = intval(array_shift($data));

for ($i = 0; $i < $num_testcases; ++$i)
{
	$num_points = intval(array_shift($data));
	$look = array();
	for ($j = 0; $j < $num_points; ++$j)
	{
		$look[] = array_shift($data);
	}
	$h = array();
	for ($j = 0; $j < $num_points; ++$j)
	{
		$h[$j] = $look;
		unset($h[$j][$j]);
		if (!check($h[$j], $look[$j]))
		{
			echo('Unsafe Land.');
			continue 2;
		}
	}
	echo('Safe Land.');
}

function sign ($num)
{
	if ($num === 0)
	{
		return 0;
	}
	return abs($num)/$num;
}

function check ($points, $point)
{
	$check_point = array_map('intval', explode(' ', $point));
	$check_x = $check_point[0];
	$check_y = $check_point[1];

	$int_points = array();
	foreach ($points as $a_point)
	{
		$data = array_map('intval', explode(' ', $a_point));
		if (sign($data[0]) === sign($check_x) && sign($data[1]) === sign($check_y))
		{
			$int_points[] = array('x' => $data[0], 'y' => $data[1]);
		}
	}
	if (sizeof($int_points) > 1)
	{
		return false;
	}
	else
	{
		return true;
	}
}

?>