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: Wrong Answer)

#include<deque>
#include<queue>
#include<vector>
#include<algorithm>
#include<iostream>
#include<set>
#include<cmath>
#include<tuple>
#include<string>
#include<chrono>
#include<functional>
#include<iterator>
#include<random>
#include<unordered_set>
#include<array>
#include<map>
#include<iomanip>
#include<assert.h>
#include<bitset>
#include<stack>
#include<memory>
using namespace std;
typedef long long ll;
#define EPS (1e-7)
#define INF (1e9)
#define PI (acos(-1))

int n, m;
//char maze[101][101];
typedef pair < int, int> P;
//int sx, sy, gx, gy;
//int d[101][101];
//int dx[4] = { 1,0,-1,0 };
//int dy[4] = { 1,0,-1,0 };

//const ll mod = 1000000007;

int main()
{
	int a, b;
	cin >> n>>m;
	vector<P> city(m);
	vector<int> help(m);
	for (int i = 0; i < m; i++) {
		cin >> city[i].first>>city[i].second;
		help[i] = city[i].second;
	}
	sort(help.begin(), help.end());
	for (int i = 0; i < m; i++) {
		for (int j = 0; j < m; j++) {
			//cout << help[j] << " " << city[i].second << endl;
			if (help[j] == int(city[i].second)) {
				printf("%06d", int(city[i].first));
				printf("%06d\n", j+1);
				break;
			}
		}
		//cout << "work" << endl;
	}
	
	
}