Problem:
Score: 300 points

Problem Statement

In Republic of Atcoder, there are N prefectures, and a total of M cities that belong to those prefectures.

City i is established in year Y_i and belongs to Prefecture P_i.

You can assume that there are no multiple cities that are established in the same year.

It is decided to allocate a 12-digit ID number to each city.

If City i is the x-th established city among the cities that belong to Prefecture i, the first six digits of the ID number of City i is P_i, and the last six digits of the ID number is x.

Here, if P_i or x (or both) has less than six digits, zeros are added to the left until it has six digits.

Find the ID numbers for all the cities.

Note that there can be a prefecture with no cities.

Constraints

1 \leq N \leq 10^5

1 \leq M \leq 10^5

1 \leq P_i \leq N

1 \leq Y_i \leq 10^9

Y_i are all different.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
P_1 Y_1
:
P_M Y_M

Output

Print the ID numbers for all the cities, in ascending order of indices (City 1, City 2, ...).

Sample Input 1

2 3
1 32
2 63
1 12

Sample Output 1

000001000002
000002000001
000001000001

As City 1 is the second established city among the cities that belong to Prefecture 1, its ID number is 000001000002.

As City 2 is the first established city among the cities that belong to Prefecture 2, its ID number is 000002000001.

As City 3 is the first established city among the cities that belong to Prefecture 1, its ID number is 000001000001.

Sample Input 2

2 3
2 55
2 77
2 99

Sample Output 2

000002000001
000002000002
000002000003

Solution in PHP7 (7.0.15) (judge verdict: Time Limit Exceeded)

<?php
list($n, $m) = explode(" ", fgets(STDIN));
$array = [];
$country_array = array_fill(1, $n, $array);
for($i=0;  $i<$m; $i++){
	$ar = explode(" ", trim(fgets(STDIN)));
	$country_array[$ar[0]][]= $ar[1];
	$array[] = $ar;
}

foreach ($country_array as $key=>$arr) {
	sort($arr);
	$sorted_country_array[$key] =$arr;
}

foreach ($array as $aaa) {
	$num1 = $aaa[0];
	$num2 = $aaa[1];
	$num3 = array_search($num2, $sorted_country_array[$num1])+1;
	echo make_ans_num($num1, $num3) . "\n";
}



// 0うめする関数
function make_ans_num ($num1, $num2){
	$leftnum = sprintf('%06d', $num1);
	$rightnum = sprintf('%06d', $num2);
	return $leftnum . $rightnum;
}