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: Time Limit Exceeded)

#include<stdio.h>
int main(void)
{
    long N,M,i,j;
    long P[100001],Y[100001],y[100001];

    //入力
    scanf("%ld %ld",&N,&M);
    i=1;
    while(i<=M)
    {
        scanf("%ld %ld",&(P[i]),&(Y[i]));
        i++;
    }

    i=1;
    while(i<=M){
        y[i]=1;
        j=1;
        while(j<=M){
            if(P[j]==P[i] && Y[j]<Y[i]){
                y[i]++;
            }
            j++;
        }
        i++;
    }

    //出力
    i=1;
    while(i<=M){
        if(1<=P[i] && P[i]<=9){
            printf("00000%1ld",P[i]);
        }else if(10<=P[i]  && P[i]<=99){
            printf("0000%2ld",P[i]);
        }else if(100<=P[i]  && P[i]<=999){
            printf("000%3ld",P[i]);
        }else if(1000<=P[i]  && P[i]<=9999){
            printf("00%4ld",P[i]);
        }else if(10000<=P[i] && P[i]<=99999){
            printf("0%5ld",P[i]);
        }else{
            printf("%6ld",P[i]);
        }

        if(1<=y[i] && y[i]<=9){
            printf("00000%1ld\n",y[i]);
        }else if(10<=y[i]  && y[i]<=99){
            printf("0000%2ld\n",y[i]);
        }else if(100<=y[i]  && y[i]<=999){
            printf("000%3ld\n",y[i]);
        }else if(1000<=y[i]  && y[i]<=9999){
            printf("00%4ld\n",y[i]);
        }else if(10000<=y[i] && y[i]<=99999){
            printf("0%5ld\n",y[i]);
        }else{
            printf("%6ld\n",y[i]);
        }
        i++;
    }
    return 0;
}