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)

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<vector>
#include<functional>
#include<algorithm>
#include<stdlib.h>
#include<string>
#include<cmath>
#include<deque>
#include<map>

using namespace std;
typedef long long ll;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define all(_x) _x.begin(), _x.end()
#define r_sort(_x) sort(_x.begin(), _x.end(), std::greater<int>())
#define INF 1LL << 60
#define MAX 1000000000
const int MOD = 1000000007;
int main(void) {
	int N, M, p, y, c;
	map<pair<int, int>, int> num;
	vector<pair<int, int> > data, data2;
	scanf("%d%d", &N, &M);
	rep(i, 0, M) {
		scanf("%d%d", &p, &y);
		data.push_back(make_pair(p, y));
		data2.push_back(make_pair(p, y));
	}
	sort(all(data2));
	p = 0;
	for (auto v : data2) {
		if (v.first != p)c = 0;
		num[v] = v.first * 1000000 + ++c;
		p = v.first;
	}
	for (auto v : data) {
		printf("%012d\n", num[v]);
	}
	return 0;
}
int gcd(int a, int b)
{
	if (a < b) {
		a ^= b;
		b ^= a;
		a ^= b;
	}

	return b ? gcd(b, a % b) : a;
}
long long modpow(long long a, long long n) {
	long long res = 1;
	while (n > 0) {
		if (n & 1) res = res * a % MOD;
		a = a * a % MOD;
		n >>= 1;
	}
	return res;
}/*
int main() {
	int N, K;
	ll s = 0;
	scanf("%d%d", &N, &K);
	rep(l, 1, K + 1) {
		s += (modpow(K - l + 1,N) - modpow(K - l, N)) % MOD + modpow(K / l, N - 1) * (l - 1);
		printf("%lld %lld \n",s, (modpow(K - l + 1, N) - modpow(K - l, N)) % MOD, N - 1);
		s %= MOD;
	}
	printf("%lld\n", s);
	return 0;
}*/