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 Java8 (OpenJDK 1.8.0) (judge verdict: Time Limit Exceeded)

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;


public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int PiNum = scan.nextInt();
		int Test_case = scan.nextInt();
		
		int inputs[][] = new int [Test_case][2];
		Map<Integer,List<Integer>> map = new TreeMap<Integer,List<Integer>>();
		int piId = 0;
		int cityId = 0;
		for (int i = 0; i < Test_case; i++)
		{
			piId = scan.nextInt();
			cityId = scan.nextInt();
			inputs[i][0] = piId;
			inputs[i][1] = cityId;
			if (map.get(piId) == null)
			{
				List<Integer> li = new ArrayList<Integer>();
				li.add(cityId);
				map.put(piId, li);
			}else{
				
				map.get(piId).add(cityId);
			}
			
		}
		
		Iterator<Integer> it = map.keySet().iterator();
		 
		while(it.hasNext())
		{
			Collections.sort(map.get(it.next()));
			
			//System.out.println(it.next());
		}
		List<Integer> arry = null;
		int index = 0;
		int pi = 0;
		//String result1;
		//String result2;
		for (int i = 0; i <inputs.length ; i++)
		{
			pi = inputs[i][0];
			arry = map.get(pi);
			index = arry.indexOf(inputs[i][1]);
			
			System.out.println(caclResult(pi)+caclResult(index+1));
		}
		
	}
	
	private static String caclResult (int i)
	{
		StringBuffer res = new StringBuffer();
		for (int m = 0; m < 6-(i+"").length(); m++)
		{
			res.append("0");
		}
		
		res.append(i);
		
		return res.toString();
	}
	
}