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 Pascal (FPC 2.6.2) (judge verdict: Wrong Answer)

var
	a,b,x,y,num:array[0..100010] of longint;
	n,m,i,t:longint;
	ch:string[20];
procedure qsort(l,r:longint);
var
	i,j,k,l1,t,mid:longint;
begin
	i:=l; j:=r;
	mid:=(l+r) div 2;
	repeat
		while (x[i]<x[mid]) or (x[i]=x[mid]) and (y[i]<y[mid]) do inc(i);
		while (x[j]>x[mid]) or (x[j]=x[mid]) and (y[j]>y[mid]) do dec(j);
		if i<=j then
		begin
			t:=x[i]; x[i]:=x[j]; x[j]:=t;
			t:=y[i]; y[i]:=y[j]; y[j]:=t;
			for k:=1 to m do
				if num[k]=i then break;
			for l1:=1 to m do
				if num[l1]=j then break;
			t:=num[k]; num[k]:=num[l1]; num[l1]:=t;
			inc(i); dec(j);
		end;
	until i>j;
	if l<j then qsort(l,j);
	if i<r then qsort(i,r);
end;
procedure card(x,y:longint);
var
	i,t:longint;
begin
	str(x,ch);
	t:=6-length(ch);
	for i:=1 to t do write(0);
	write(x);
	str(y,ch);
	t:=6-length(ch);
	for i:=1 to t do write(0);
	writeln(y);
end;
begin
	read(n,m);
	for i:=1 to m do 
	begin 
		read(a[i],b[i]);
		x[i]:=a[i];
		y[i]:=b[i];
		num[i]:=i;
	end;
	qsort(1,m);
	t:=1;
	y[1]:=t;
	for i:=2 to m do
	begin 
		if x[i]<>x[i-1] then t:=1 else inc(t);
		y[i]:=t;
	end;
	for i:=1 to m do card(x[num[i]],y[num[i]]);
end.