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.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		
		int[] intArray1 = new int[m];
		int[] intArray2 = new int[m];
		int[] intArray4 = new int[m];
		
	
		for(int i=0; i < m; i++) {
		    int s = sc.nextInt();
		    intArray1[i] = s;
		    int k = sc.nextInt();
		    intArray2[i] = k;
		    
		}
		for(int j=0; j < m; j++) {
			int[] intArray3 = new int[m];
			int count2 = 0;
			if(!Arrays.asList(intArray4).contains(intArray1[j])){
			
			int count = 0;
			for(int k=1; k < m; k++) {
				if(intArray1[j] == intArray1[k] && k != j && j < k) {
					
					intArray3 [count] = intArray2[k];
					count = count + 1;
					}
			}
			Arrays.sort(intArray3);
			
			for(int l=0; l < m; l++) {
				for(int o=0; o < intArray3.length; o++) {
				if(intArray3[o] == intArray2[l]) {
					intArray2[l] = o + 1;
				}
				}
			}
			intArray4[count2] = intArray1[j];
			}
		}
		for(int p=0; p < m; p++) {
			int intA = String.valueOf( intArray1[p] ).length(); 
			int intB = String.valueOf( intArray2[p] ).length(); 
			String result1 = "";
			String result2 = "";
			while(6 > intA) {
				result1 = result1 + "0";
			}
			while(6 > intB) {
				result2 = result2 + "0";
			}
			result1 = result1 + String.valueOf(intArray1[p]);
			result2 = result2 + String.valueOf(intArray2[p]);
			System.out.println(result1 + result2);
		}
	}
		
}