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 Julia (0.5.0) (judge verdict: Time Limit Exceeded)

lines=readlines()
N,M=map(x->parse(Int,x),split(shift!(lines)))
A=[Array{Pair{Int,Int}}(0) for _=1:N]
P=Array{Int}(0)
for i=1:M
	p,y=map(x->parse(Int,x),split(shift!(lines)))
	push!(A[p],y=>i)
	push!(P,p)
end
ans=Array{Int}(M)
for i=1:N
	sort!(A[i])
	for j=1:length(A[i])
		ans[A[i][j].second]=j
	end
end
function f(x)
	s=Array{Char}(0)
	while x>0
		push!(s,Char(x%10+48))
		x=div(x,10)
	end
	while length(s)<6
		push!(s,'0')
	end
	reverse!(s)
	for c=s
		print(c)
	end
end
for i=1:M
	f(P[i])
	f(ans[i])
	println()
end