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 C (GCC 5.4.1) (judge verdict: Time Limit Exceeded)

#include<stdio.h>
typedef struct{
  int pren;
  int year;
  int num;
} cityinfo;

int main()
{
  int i, n, m;
  scanf("%d%d", &n, &m);
  cityinfo city[m];
  for(i = 0; i < m; ++i){
    scanf("%d%d", &city[i].pren, &city[i].year);
  }
  for(i = 0; i < m; ++i){
    city[i].num = 0;
  }
  int j;
  for(i = 0; i < m; ++i){
    for(j = i+1; j < m; ++j){
      if(city[i].pren == city[j].pren){
	if(city[i].year > city[j].year) city[i].num += 1;
	else city[j].num += 1;
      }
    }
  }
  for(i = 0; i < m; ++i) printf("%06d%06d\n", city[i].pren, city[i].num+1);

  return 0;
}