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 Lua (5.3.2) (judge verdict: Wrong Answer)

local zones = io.read("*n")
local num = io.read("*n")
local data = {}
for j = 1,num do
	local idx = io.read("*n")
	local y = io.read("*n")
	local d = {n = 0, year = y,i=j,z = idx}
	table.insert(data,d)
end
local tmp = {}
table.sort(data,function(a,b)
 	return a.year < b.year
end)

-- for k,v in ipairs(data) do
-- 	v.k = k
-- end
for k,v in ipairs(data) do
	if not tmp[v.z] then
		tmp[v.z] = 1
	else
		tmp[v.z] = tmp[v.z] + 1
	end
	v.n = tmp[v.z]
end

local x = {}
for k,v in pairs(data) do
	x[v.i]={v.z,v.n}
end

for i = 1,#x do
	local digits = 0
	if x[i][1] < 100000 then
		local num = x[i][1]

		for i= 1,5 do
			num = num/10
			if num >= 10 then
				digits = digits + 1
			end
		end
	end
	x[i][1] = string.rep("0",5-digits)..x[i][1]
	if x[i][2] < 100000 then
		local num = x[i][2]
		for i= 1,5 do
			num = num/10
			if num >= 10 then
				digits = digits + 1
			end
		end
	end
	x[i][2] = string.rep("0",5-digits)..x[i][2]
	print(x[i][1]..x[i][2])
end