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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include<sstream>
#include<string>
#include<vector>
#include <cmath>
#include <limits>
#include <queue>
#include<algorithm>
#include <map>
#include <stack>
#include <iomanip>
#include <cstdio>


using namespace std;
 
#define rep(i,n) for (int (i)=0;(i)<(n);i++)


/*int binarySearch(vector<int > v, int target){
  int l = 0, r = v.size();
  int mid;
  while (l+1<r){
    mid = (r+l)/2;
    if (v[mid] <= target){
      l = mid;
    }
    else r = mid;
  }
  return l;
}*/


int main(){
  int n, m;
  cin >> n >> m;
  int p[m];
  int y[m];
  vector<int> id[n];
  rep(i,m){
    scanf("%d%d", &p[i], &y[i]), id[p[i]-1].push_back(y[i]);
  }
  rep(i,n){
    sort(id[i].begin(),id[i].end());
  }

  int res;
  rep(i,m){
    res = lower_bound(id[p[i]-1].begin(), id[p[i]-1].end(), y[i])-id[p[i]-1].begin();
    cout<< setfill('0') << setw(6)  << p[i];
    cout << setfill('0') << setw(6)  << res+1 << endl;
  }  
  return 0;
}