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: Wrong Answer)

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
#include <time.h>
typedef long long llint;
typedef long double ldouble;
// int compare(const void *a, const void *b){return *(llint *)a - *(llint *)b;}
typedef struct{
    llint aa;// p
    llint bb;// y 
    llint cc;// city number
    llint id;
}frequent;
int cmp1( const void *p, const void *q ){
    return ((frequent*)p)->aa - ((frequent*)q)->aa == 0 ? ((frequent*)p)->bb - ((frequent*)q)->bb : ((frequent*)p)->aa - ((frequent*)q)->aa;
}
int cmp2( const void *p, const void *q ){
    return ((frequent*)p)->cc - ((frequent*)q)->cc;
}


int main(void){
    llint n,m,i;
    scanf("%lld%lld",&n,&m);
    frequent city[m];
    for(i=0;i<m;i++){
        scanf("%lld",&city[i].aa);
        scanf("%lld",&city[i].bb);
        city[i].cc = i;
    }
    qsort(city,m,sizeof(frequent),cmp1);
    for(i=0;i<m;i++){
        printf("%lld\n",city[i].bb);
    }
    for(i=0;i<m;i++){
        if(i==0){
            city[i].id = city[i].aa*pow(10,6)+1;
            continue;
        }
        if(city[i].aa == city[i-1].aa){
            city[i].id = city[i-1].id + 1;
        }else{
            city[i].id = city[i].aa*pow(10,6)+1;
        }
        // printf("%lld\n",city[i].id);
    }
    qsort(city,m,sizeof(frequent),cmp2);
    for(i=0;i<m;i++){
        printf("%012lld\n",city[i].id);
    }



    // printf("\n");
    return 0;
}