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 C (GCC 5.4.1) (judge verdict: Accepted)


#include <stdio.h>
#include <stdlib.h>
#include <math.h>

struct tosi {
	int idnum;
	int p;
	int y;
} ;

int compare_tosi(const void *a, const void *b) {
  struct tosi *A = (struct tosi *)a;
  struct tosi *B = (struct tosi *)b;
  return A->y - B->y;
}



int main(void)
{
	//変数の宣言
	int n,m;
	static int num[100010];
	static int pcopy[100010];
	static int ncopy[100010];
	int i;
	static struct tosi tosis[100010];
	
	
	//データの読み込み
	scanf("%d %d",&n,&m);
	for(i=0;i<m;i++){
		scanf("%d %d",&tosis[i].p,&tosis[i].y);
		tosis[i].idnum=i+1;
		pcopy[i+1]=tosis[i].p;
	}
	
	
//	printf("nは%dです\n", n);
//	printf("データの読み込み終了\n");
	//実際の処理
	
	
	qsort(tosis, m, sizeof(struct tosi), compare_tosi);
	
	
//	for(i=0;i<m;i++){
//		printf("idnum=%d p=%d y=%d\n",tosis[i].idnum,tosis[i].p,tosis[i].y);
//	}
	
	
	
	for(i=0;i<m;i++){
		num[tosis[i].p]++;
		ncopy[tosis[i].idnum]=num[tosis[i].p];
//		printf("idnum=%d p=%d ncopy=%d\n",tosis[i].idnum,tosis[i].p,num[tosis[i].p]);
	}
	
//	for(i=1;i<m+1;i++){
//		printf("idnum=%d p=%d ncopy=%d\n",i,pcopy[i],ncopy[i]);
//	}
	
	
	
//	printf("計算部分終了\n");
	
	//出力
	
	for(i=1;i<m+1;i++){
		printf("%06d%06d\n",pcopy[i],ncopy[i]);
	}
	
//	printf("結果の出力終了\n");
	
	return 0;
}