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: Runtime Error)

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Scanner;


public class Main {
	static int N,M;
	static int[][] arr;
	static boolean[] visited;
	static int count;
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc=new Scanner(System.in);
		N=sc.nextInt();
		M=sc.nextInt();
		arr=new int[N+1][100];
		visited=new boolean[N+1];
		int[] orginal=new int[M];
		Map<Integer, String> result = new LinkedHashMap<Integer, String>();

		for(int i=0;i<M;i++) {
			int x=sc.nextInt();
			int y=sc.nextInt();
			orginal[i]=y;
			arr[x][y]=1;
			}
		
		for(int i=1;i<=N;i++) {
			visited[i]=true;
			count=1;
			for(int j=1;j<100;j++) {
				if(arr[i][j]==1) {
					String xiaquid = String.format("%06d",Integer.valueOf(i));
					String cityorder = String.format("%06d",Integer.valueOf(count));
					String cityid=xiaquid+cityorder;
					result.put(j, cityid);
					count++;
				}
			}
		}
		for(int i=0;i<M;i++) {
			System.out.println(result.get(orginal[i]));
			}
		}
}