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 Ruby (2.3.3) (judge verdict: Wrong Answer)

n,m=gets.chomp.split(" ").map { |e| e.to_i }
py = []

m.times do |i|
  p,y=gets.chomp.split(" ").map { |e| e.to_i }
  py[i] = {"py" => ("%06d" % p) + ("%06d" % y) ,"i" => i, "p" => p}
end


def quick_sort_hash(c,x)
  if c==[]
    return []
  end
  smaller = c.select{ |h| h[x] < c[0][x] }
  larger = c.select { |h| h[x] > c[0][x] }

  return quick_sort_hash(smaller,x) + [c[0]] +  quick_sort_hash(larger,x)

end

a = quick_sort_hash(py,"py")


ans = []
temp = 1
hoge = 1

for x in a do
  if hoge != x["p"]
    hoge = x["p"]
    temp = 1
  end
  ans[x["i"]] = ("%06d" % x["p"]) + ("%06d" % temp)
  temp += 1
end

puts ans