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 PyPy3 (7.3.0) (judge verdict: Accepted)

"""
M <= 10 ** 5
なので全探索しても間に合いそう。
"""
N, M = map(int, input().split())
input_li = []   # 入力[p, y]の組み合わせを格納する二次元リスト
p_dict = {}     # pごとのyのリストを格納する辞書
ans_dict = {}   # キーp, yを指定することでIDが取り出せる辞書

# 入力をinput_liに詰めつつp_dictを作っていく
for _ in range(M):
    p, y = map(int, input().split())
    input_li.append([p, y])
    if p not in p_dict:
        li = [y]
        p_dict[p] = li
    else:
        p_dict[p].append(y)

# p_dictを元にans_dictを作っていく
for p in p_dict:
    li = sorted(p_dict[p])
    ans_dict[p] = {}
    for i in range(len(li)):
        p_id = '0' * (6 - len(str(p))) + str(p)
        c_id = '0' * (6 - len(str(i + 1))) + str(i + 1)
        ans_dict[p][li[i]] = p_id + c_id

# input_li順にIDを出力していく
for p, y in input_li:
    print(ans_dict[p][y])