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)

attrs = Array.new
while line = $stdin.gets
attrs << line.chomp.split
end
p attrs
attrs = [["2", "3"], ["1", "32"], ["2", "63"], ["1", "12"]]
attrs.delete_at(0)
shilist = attrs.map {|item| item.map(&:to_i) }
shilist.length.times{|n| shilist[n].push(n+1)}
#shilist[n]=[県,年,市番号,県ごとの順番]
shilist.sort! do |a, b| 
  (a[0] <=> b[0]).nonzero? || (a[1] <=> b[1])
end
kennum = shilist[0][0]
t=1
kakou = shilist.each{|item|
if item[0] == kennum then
  item.push(t)
  t=t+1
else
  item.push(1)
  t = 1
end
kennum=item[0]
}
kakou.sort!{ |a, b| a[2] <=> b[2] }
kakou.each{|item|
print sprintf("%06d",item[0]),sprintf("%06d",item[3]),"\n"
}