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 (Clang 3.8.0) (judge verdict: Runtime Error)

#include<stdio.h>

void bubblesort(long int a[],int N){
    for(int i=0; i<N-1; i++){
        for(int j=0; j<N-1; j++){
            if(a[j+1]<a[j]){
                int swap = a[j];
                a[j] = a[j+1];
                a[j+1] = swap;
            }
        }
    }

    /*for(int i=0; i<N; i++){
        printf("%d\n", a[i]);
    }*/
}

void specialsort(long int a[],int N){
    long int arr[100000],count=0;
    for(int i=0; i<N; i++){
        if(a[i]!=0){
            arr[count] = a[i];
            count++;
        }
    }
    bubblesort(arr,count);
    for(int j=0; j<count; j++){
        for(int i=0; i<N; i++){
            if(a[i]==arr[j]){
                a[i] = j+1;
            }
        }
    }
}


int main(void){
    long int prefectureNum, statesNum;
    scanf("%ld%ld",&prefectureNum, &statesNum);
    long int P[statesNum], Y[statesNum];
    for(int i=0; i<statesNum; i++){
        scanf("%ld%ld",&P[i], &Y[i]);
    }
    long int len = prefectureNum+1;
    // 配列定義の際、長さを計算式で指定してはいけない
    long int arr[len][len], count=0;
    for(int i=1; i<=prefectureNum; i++){
        for(int j=0; j<statesNum; j++){
            if(P[j] == i){
                arr[i][j] = Y[j];
                //printf("%d\n", arr[i][j]);
            }
        }
        specialsort(arr[i], len);
    }

    for(int i=0; i<statesNum; i++){
        printf("%06ld", P[i]);
        printf("%06ld\n", arr[P[i]][i]);
    }

    return 0;
}