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 9.2.1) (judge verdict: Runtime Error)

#include <stdio.h>

int main (void){
 
    long int tmp2;
    //long int num[100001][100001];
    int pref, input, tmp1;//
    //int cnt[100001][100001] = {0}, loger[100001][10], citycnt[100001] = {0};
  
    /*for(int i = 0; i < 10; i++){  
        for(int j = 0; j < 10; j++){  
            printf("%d\n", cnt[i][j]);
        }
    }*/
  
    scanf("%d", &pref);
    scanf("%d", &input);

    long int num[pref + 1][input + 1];
    int citycnt[pref + 1], loger[input + 1][10];
    int cnt[pref + 1][input + 1];

    //printf("%d\n", sizeof(num) / sizeof(num[0][0]));
    //printf("%d\n", sizeof(citycnt) / sizeof(citycnt[0]));
    //printf("%d\n", sizeof(loger) / sizeof(loger[0][0]));
    //printf("%d\n", sizeof(cnt) / sizeof(cnt[0][0]));

    for(int i = 0; i <= pref; i++){  
        citycnt[i] = 0;
        for(int j = 0; j < input; j++){  
            cnt[i][j] = 0;
        }
    }
  
    for(int i = 0; i < input; i++){
        scanf("%d", &tmp1);
        scanf("%ld", &tmp2);
    
        loger[i][1] = tmp1;
        loger[i][2] = citycnt[tmp1];
        num[tmp1][citycnt[tmp1]] = tmp2;
        //printf("%d %d %ld %ld\n", tmp1, loger[i][2], tmp2, num[tmp1][citycnt[tmp1]]);
        citycnt[tmp1]++;
    }
  
    /*for(int i = 0; i <= pref; i++){
        printf("%d %d\n", i, citycnt[i]);
    }*/
  
    for(int i = 0; i <= pref; i++){
        for(int j = 0; j < citycnt[i]; j++){
        //printf("%ld\n", num[i][j]);
        for(int k = 0; k < citycnt[i]; k++){
            if(num[i][j] >= num[i][k]){
            cnt[i][j]++;
	        //printf("%d\n", cnt[i][j]);
            }
        }
        //printf("%d %d\n", i, j);
        //printf("%d\n", cnt[i][j]);
        }
    }
  
    for(int i = 0; i < input; i++){
        printf("%06d%06d\n", loger[i][1], cnt[loger[i][1]][loger[i][2]]);
    }
    
    return 0;
}